Make them more of a threat. Make their targeting more aggressive and never stutter. Make them harder to take down. Make them an actual line of defense against dives if the champion(s) being dived can outmaneuver and outsmart their opponents.
The reason why we can't have an ADC meta is everything melts. Including turrets.
The reason we can't have an assassin meta is because assassins blow up anyone they wish under turrets, being able to tank/avoid 6 or 7 shots to the face mid-game with hardly any defensive stats.
The reason we can't have a support meta is because ADCs are turret munching machines.
The reason we can't have a bot lane meta in general is because you can't really punish the enemy team for 4 manning bot lane because dives are easy to pull off thanks to poor turret target juggling and how easy they are to take down.
The reason we can't have a tank meta is because most tanks and juggernauts literally stop caring about turrets after their second armor item.
The reason we can't have fun playing strategically these days is because playing safe is no longer an option. Teleport has become a crutch for laners who need to port back to avoid that 6 minute turret. Junglers can oscillate dramatically between useless and absolutely stupid broken because of how easy it is to push a turret. Games are pre-decided and feel that way because turrets don't stay up long enough to allow losing teams to recover from an ace.
So before we decide to ask for nerf or buffs to any champion class or items, remember where the real problem in the meta is.