Here's how Riot should balance ADCs (both melee and ranged)
Instead of making every melee carry extremely binary and frustrating to play against (Tryn, Yasuo, Fiora, etc), make melee carries the ONLY auto-attackers with steroids of any kind (Yi, Jax, Irelia, etc).
At the same time, instead of giving every single ranged ADC absurdly valued steroids, give them absolutely no offensive steroids as a trade-off for the safety of range. Give them tools to kite/outplay instead, as that's the main reason you should be taking a ranged ADC over a melee one.