The kind of changes (suggestion) I would like to see from Riot
To address the "tankiness is shit" problem.
I feel the main problem is that resistances feel worthless to buy yet they are the counter to assassins/burst champions. Indirectly if we nerf what rapes tankiness (sustained true damage) we allow people to be more secure about taking some tankiness and surviving bursters, making the meta less one-shot + tanks melted oriented.
So here's a few random suggestions
CONQUEROR'S
bonus AD : removed True damage conversion : removed Now gives 20% armor and magic penetration, along with 8% of premitigation damage healing against champions.
idea -> remove the hard tank melting in favour of much softer one, with help to fight tanks with low damage, in sololane, thanks to "premitigation damage lifesteal". Overall remains powerful against tanks, but doesn't melt them quite as hard. Open up for AP users. Solidify the identity as a lategame rune ( ad removed )

R - Last Breath :
Physical damage : 200/300/400 -> 215/330/445 Bonus armor penetration on crits : 50% -> 30%
idea : very slightly more upfront burst for compensation, fairly less armor-melting. With this + conqueror change it will no longer be trolling to take armor into yasuo.

Vitals damage : 2.5% (+4.5% per 100 AD) true damage -> 3.5% (+6 % per 100 AD) physical damage with added 40% total armor pen on vital hits exclusively.
idea : open up armorpen buildpath, reduce the "building resistances against her is literally trolling" aspect. Remains powerful lategame tank melter.

E - Wuju style
Active : Gains 18 / 26 / 34 / 42 / 50 (+ 35% bonus AD) true damage -> Gains 25/35/45/55/65 (+40% bonus AD) physical damage on-hit. While Wuju style is active, Yi gains 25% total armor penetration.

W - Silver bolts : Reverted to an iteration where it includes base damage as opposed to only %max health damage
Damage : 4 / 6.5 / 9 / 11.5 / 14% of target's maximum health in true damage -> ( 20/30/40/50/60 + 4/5/6/7/8 % of target's maximum health ) in true damage
R - Final Hour
Tumble 50% cooldown reduction : removed Bonus AD : 20/30/40 -> 20/35/50 (as compensation)

True damage conversion on crits : removed Crits now deal 240% damage.