Riven/Kled have not gotten any damage buffs in the past 1 year and 2 months, there counterparts have
The last Riven damage buff was on patch 7.24, so basically zero damage buffs in season 8, same with Kled back in 7.22
Let's go down the list of there counterparts
Darius:
V8.4 Crippling Strike Crippling Strike Cooldown reduced to 7 / 6.5 / 6 / 5.5 / 5 seconds from 9 / 8 / 7 / 6 / 5. AD ratio increased to 40 / 45 / 50 / 55 / 60% AD from 40% AD at all ranks. BUG FIX: Fixed a bug where it sometimes failed to damage certain units (e.g YorickSquare Yorick's Dark Procession Dark Procession). Apprehend Apprehend Armor penetration increased to 10 / 15 / 20 / 25 / 30% from 5 / 10 / 15 / 20 / 25%.
V8.19 Crippling Strike Crippling Strike AD ratio increased to 50 / 55 / 60 / 65 / 70% AD from 40 / 45 / 50 / 55 / 60% AD. Apprehend Apprehend Armor penetration increased to 15 / 20 / 25 / 30 / 35% from 10 / 15 / 20 / 25 / 30%.
Fiora:
V8.17 Bladework Bladework Modified critical strike damage increased to 160 / 170 / 180 / 190 / 200% from 140 / 155 / 170 / 185 / 200%.
V8.19 - September 26th Hotfix Duelist's Dance Duelist's Dance Heal increased to 40 − 115 (based on level) from 35 − 110 (based on level). V8.19 Duelist's Dance Duelist's Dance Heal increased to 35 − 110 (based on level) from 25 − 110 (based on level). Lunge Lunge BUG FIX: Now once again correctly prioritize champions and vital procs over killable minions.
Gragas (yes top lane gragas is a thing, or mid lane gragas, none the less it's still a matchup):
V8.7 Barrel Roll Barrel Roll AP ratio increased to 70% AP from 60% AP. Drunken Rage Drunken Rage AP ratio increased to 50% AP from 30% AP. NEW EFFECT: Damage reduction now scales with 4% per 100 AP. Gragas OktoberfestCircle Oktoberfest Gragas BUG FIX: Seam lines have been minimized.
V8.13 Drunken Rage Drunken Rage Cooldown changed to 5 seconds at all ranks from 8 / 7 / 6 / 5 / 4. NEW EFFECT: Now gains 50 bonus range for his next attack.
Poppy:
V8.4 Iron Ambassador Iron Ambassador Base damage increased to 20 − 180 (based on level) from 10 − 180 (based on level). Heroic Charge Heroic Charge Base damage increased to 60 / 80 / 100 / 120 / 140 from 55 / 75 / 95 / 115 / 135.
V8.9 Stats Base movement speed reduced to 340 from 345. Iron Ambassador Iron Ambassador Buckler bonus range increased to 350 from 300. Steadfast Presence Steadfast Presence Bonus movement speed reduced to 30% at all ranks from 32 / 34 / 36 / 38 / 40%. Increased armor ratio reduced to 10% total armor from 15%. Increased magic resistance ratio reduced to 10% total magic resistance from 15%. Heroic Charge Heroic Charge Range increased to 475 from 425. Keeper's Verdict Keeper's Verdict NEW EFFECT: Uncharged attack now makes the enemies targetable. Uncharged attack knockup duration reduced to 0.75 seconds from 1. Base damage reduced to 200 / 300 / 400 from 210 / 310 / 410. Charged missile speed increased to 2000 from 1600.
V8.12 Iron Ambassador Iron Ambassador Cooldown reduced to 16 / 12 / 8 seconds from 16 / 13 / 10. Hammer Shock Hammer Shock Cooldown reduced to 8 / 7 / 6 / 5 / 4 seconds from 9 / 8 / 7 / 6 / 5. Bonus AD ratio increased to 90% bonus AD from 80%.
Renekton:
V8.4 Reign of Anger Reign of Anger BUG FIX: Fixed a bug where his abilities failed to grant him the correct amount of Fury when initiating combat. Cull the Meek Cull the Meek Base damage increased to 65 / 100 / 135 / 170 / 205 from 65 / 95 / 125 / 155 / 185. Empowered base damage increased to 100 / 150 / 200 / 250 / 300 from 95 / 140 / 185 / 230 / 275.
V8.18 Slice Slice and Dice Fury-enhanced base damage increased to 70 / 115 / 160 / 205 / 250 from 60 / 105 / 150 / 195 / 240. Fury-enhanced armor reduction increased to 25 / 27.5 / 30 / 32.5 / 35% armor from 15 / 20 / 25 / 30 / 35%.
Rengar:
V8.5 Unseen Predator Unseen Predator Ferocity fall-off timer increased to 8 seconds from 6. NEW EFFECT: Only the spell used to gain full Ferocity is locked out. Lockout duration on gaining full Ferocity for Savagery Savagery and Bola Strike Bola Strike reduced to 0.1 seconds from 0.25. Savagery Savagery Base damage increased to 30 / 60 / 90 / 120 / 150 from 20 / 50 / 80 / 110 / 140. AD ratio changed to 0 / 5 / 10 / 15 / 20% AD from 10% AD at all ranks. BUG FIX: Fixed a bug where the empowered attack frame was slightly faster than base Savagery. BUG FIX: Fixed a bug where Tiamat item Tiamat could sometimes cause his basic attacks to use Savagery's animation. BUG FIX: If Rengar was basic attacking a target before casting a spell, he'll now continue stabbing them when the spell completes rather than forgetting what he was doing and standing around awkwardly.
V8.6 Unseen Predator Unseen Predator Lockout duration after using Savagery 2 Empowered Savagery and Bola Strike 2 Empowered Bola Strike reduced to 0.1 seconds from 0.25. Lockout only applies to the slot of the empowered ability. BUG FIX: Fixed a bug where gaining 4 ferocity from a leap Savagery Q while in the middle of Bola Strike E's cast time would cause Rengar to lose all ferocity without getting an empowered spell. BUG FIX: Can no longer leap after Hexflash Hexflashing out of a brush. Added 5 more VO lines for when Rengar gains a Bonetooth stack. Savagery Savagery Empowered AD ratio increased to 40% AD from 30% AD. Adjusted the animation cast frame to make canceling the animation feel better. BUG FIX: Fixed a bug where he would get 3 fast attacks if he cast Q while leaping (should only get 2). BUG FIX: Fixed a bug where he would attack again instantly after landing if he cast Q while leaping. BUG FIX: Fixed a bug where Savagery would not grant ferocity when it missed because of dodge/blind. Bola Strike Bola Strike Bonus AD ratio increased to 80% bonus AD from 70%. Empowered bonus AD ratio increased to 80% bonus AD from 70%. BUG FIX: Fixed a bug where casting Bola Strike when leaping with three ferocity would sometimes consume all ferocity without granting an empowered spell. Thrill of the Hunt Thrill of the Hunt AD ratio increased to 50% AD from 30%.
Rumble:
V8.7 Flamespitter Flamespitter Total base damage increased to 175 / 210 / 245 / 280 / 315 from 135 / 180 / 225 / 270 / 315. Damage to minions changed to 60 / 65 / 70 / 75 / 80% from 75%.
V8.12 Scrap Shield Scrap Shield Base shield strength increased to 100 / 130 / 160 / 190 / 220 from 80 / 110 / 140 / 170 / 200. AP ratio increased to 50% AP from 40% AP. The Equalizer The Equalizer Base damage increased to 140 / 210 / 280 from 130 / 185 / 240. AP ratio increased to 35% AP from 30% AP.
Sion:
V8.8 Decimating Smash Decimating Smash Base damage increased to 30 / 47.5 / 65 / 82.5 / 100 from 20 / 40 / 60 / 80 / 100. AD ratio reduced to 45 / 50 / 55 / 60 / 65% AD from 65% AD at all ranks. Maximum AD ratio reduced to 135 / 150 / 165 / 180 / 195% AD from 195% AD at all ranks.
V8.16 Soul Furnace Soul Furnace Bonus health on enemy kill increased to 4 from 3. Bonus health on large-enemies and champion takedowns increased to 15 from 10.
V8.14 Decimating Smash Decimating Smash Minimum base damage increased to 30 / 50 / 70 / 90 / 110 from 30 / 47.5 / 65 / 82.5 / 100. Maximum base damage increased to 90 / 150 / 210 / 270 / 330 from 90 / 142.5 / 195 / 247.5 / 300. Minimum AD ratio increased to 45 / 52.5 / 60 / 67.5 / 75% AD from 45 / 50 / 55 / 60 / 65% AD. Maximum AD ratio increased to 135 / 157.5 / 180 / 202.5 / 225% AD from 135 / 150 / 165 / 180 / 195% AD.
Trundle:
V8.22 Chomp Chomp Base damage increased to 20 / 35 / 50 / 65 / 80 from 20 / 30 / 40 / 50 / 60. AD ratio increased to 10 / 20 / 30 / 40 / 50% AD from 0 / 10 / 20 / 30 / 40% AD.
Yasuo:
Steel Tempest Steel Tempest Critical strike AD ratio increased to 180% AD from 150% AD.
Riven:
V7.24 Broken Wings Broken Wings Base damage increased to 15 / 35 / 55 / 75 / 95 from 10 / 30 / 50 / 70 / 90. AD ratio increased to 45 / 50 / 55 / 60 / 65% AD from 40 / 45 / 50 / 55 / 60% AD.
Kled:
V7.24b Stats Base attack damage increased to 65 from 63. Attack damage growth increased to 3.5 from 3. Jousting Jousting Base damage increased to 35 / 60 / 85 / 110 / 135 from 25 / 50 / 75 / 100 / 125.
V7.22 Stats Base attack damage increased to 63 from 55. Base armor increased to 35 from 26. Beartrap on a Rope Beartrap on a Rope Base damage increased to 30 / 55 / 80 / 105 / 130 from 25 / 50 / 75 / 100 / 125. Pocket Pistol Pocket Pistol Base damage increased to 35 / 50 / 65 / 80 / 95 from 30 / 45 / 60 / 75 / 90. Violent Tendencies Violent Tendencies Target's maximum health ratio increased to 4.5 / 5 / 5.5 / 6 / 6.5% of target's maximum health from 4 / 4.5 / 5 / 5.5 / 6%. Jousting Jousting Base damage increased to 25 / 50 / 75 / 100 / 125 from 20 / 45 / 70 / 95 / 120.
Yes, Riven is a decent champion after you put in a thousand hours into her, and even then she's easily countered because it's getting harder and harder to surprise enemies of what you want to do against them.
Tldr: Riven/Kled are in not so healthy states
