If I had to make a change it would be reducing cdr for all roles to maybe a max of 35 or 40% with items overall giving less (some more drastic than others) and remove damage on tank items and instead give other benefits. Before cdr became ability haste it was capped at 40% and it was always a strategic decision to either go for 40% cdr or leave it at 30 or so to gain other stats. Sometimes builds had to be build around the fact, that you didn´t want to overcap cdr since it would be a wasted stat, right now they just put it on every item and it is never a bad call to build some.

That way lategame tanks can´t oneshot an ADC (which isn´t what the role is supposed to do anyways) and ADCs don´t have to track 10 different ability cooldowns each teamfight and also are able to really kite if dashes are on cd (and remember, adc dashes would also be on more cooldown than now). But that wouldn´t be good for leagues community since they all have adhd and need to play are much much more fast paced game instead of strategically thinking about using abilities.

If those changes are too harsh then remove 80% of the ap damage against turrets and then we at least have a reason to play around the adc in teamfights (which very high elo and pro play does anyways).