"If you take Storm raiders you're not going to melt his team because you don't have fervor" LOL. Maybe in silver, where y'all just stand still and AA. The moment you have Nashor's, and 3 points into Q you can reliably proc storm raiders. The movement speed is much more valuable than 60 AD.
If you're taking Fervor, it's because you're wanting a late game build. Her strongest DPS build with fervor is actually Nashor's -> Rageblade -> Runaan's -> IE -> Pen item/Botrk or if you're really fed and they don't have as much armor Nashor's -> Rageblade -> Runaan's -> IE -> shiv -> Sell Nashor's for ER.
Outside of that, i don't see Fervor making a difference. Storm raiders gives you MS and slow resistance, between that and flash you can run down the backline or anyone that's overextended. Kayle's problem at this point is MS and Utility, not damage. With an AP / Attack Speed build you still do ~1200 DPS.
Now, in regards to nerfs to Kayle, yeah she's been nerfed: Stinger got its cut cost, Fervor is barely a keystone without itemizing crit, rageblade got a cost increase and isn't AOE anymore, TLD no longer procs twice on her E due to a bug associated with a change, runaan's lost 15 on-hit dmg, soon doran's ring won't be able to be stacked, meditation got nerfed.
Kayle however is in no way "gutted." She was ungodly strong sometime in season 6, and now she's just strong lmfao. Problably a low A tier champion. The way her kit works and itemizes is inherently hard to nerf or buff without breaking her. She's balanced along the lines of ADC and High AP items. With the stinger nerf, people started running boots stinger to compensate for the nerfs, and people found that it's an extremely effective combination. 70% attack speed, 10% CDR. 45 MS. Kayle's a champion like that, you adapt your itemization depending on what's strong in the current patch. There is many workarounds to the several nerfs, and they actually gave her more build diversity.
Infact, look at 호희, Dawidsonek, Kayle 1v9, kerber0s, Im jungle /lm jungle (inactive, he comes and goes). There are plenty of high elo Kayle one tricks who are still about where they were before the nerfs, suggesting that the Nerfs weren't effective. Between my main being D5, with a 61% win rate on her, and over 8000 games on her since season 3. I think i'm painfully aware of what she can do, on pretty much any patch since maybe 3.8 or something like that.
In terms of Tryndamere, he has a really awkward two item spike. He cannot fight Kayle during the two item phase, Whether the spike is Shyv + IE, Shyv + PD, Shyv + tiamat, etc. etc. At the boots + Shyv/PD he can fight her. but the moment she has Nashor's, that kind of ends. Ofc after that PD Mallet IE itemization exists for Kayle and Trynda can really enjoy that. Ghost isn't an issue, if you overextend against anyone with ghost that you cannot directly fight you deserve to die anyway lmfao.
In terms of Tryndamere nerfs, he has been. He was a Ghostblade + Botrk champion, and the removal of the attack speed on ghostblade got rid of the early game tryndamere build that was actually oppressive. They used to build Ghostblade -> Botrk -> Zeal item -> IE in high elo and between ghost / ghostblade / Botrk / W there wasn't really much to fight that build. They also nerfed his AP ratios when they were exploitive. He still sometimes itemizes Rageblade / Gunblade despite that nerf though. But in terms of Tryndamere, spikes, and scaling, he's not in nearly as good of a spot right now after all those changes.