Imo, adcs should either get a slight buff on their armor or indirectly with gold cost/components on items. However, the issue with adcs also comes from indirect sources. Game time, bruisers with conqueror, poke being too strong at bot lane are all things that make adcs feel weaker. However, I don't agree with the way riot as trying to buff adcs in. On pbe, there were buffs to the adcs' damage (I believe they all got reverted).
You can build survivability items like Tabi and GA, but it generally won't be enough. You also can't really rush those items (at least GA) since you need crit as a hypercarry, or other items depending on what adc you play. Draven is like one of the only ones who can somewhat rush GA as a first item. If you go black cleaver as a traditional carry (onhit/crit), you lose out on the cdr. The item is also geared more towards bruisers than damage dealers. However I might try it as a substitute for LW and it could work. Zhonya only works on on hit users and ezreal.
Either way, I don't want adcs to be overbuffed or anything. I just want to be able to play my adcs on even footing. Right now, I'm just playing mid lane since it feels dumb to play crit adcs right now. Then again, I have mainly played tristana adc and she's pretty bad right now (I just saw her win ratio at literally 42.8%, 0.88% pick ratio on op.gg). I mean maybe not best site (lolgraph shows it at 45.2% win ratio), but it still shows she's weak and it could make my opinion slightly biased.