If big shields, constant kite and peeling are a staple ;
Then ADC's do not deserve the base defensive stats they have right now (health, armor, health/lvl, armor/lvl) Mr is kinda standardized so let's ignore it right now.
Discuss.
Also if we nerfed those base stats, would it be unfair compared to other carry classes such as mages, in particular DPS mages like Azir? But then why are adc's pretty much always the center of attention of peeling and shielding, are they just better right now?