@Riot: your current design philosophy combined with the fundamental design of the stats

Is dysfunctional.

AD scales too hard too fast compared to AP and Defensive stats. AD and how it interacts with auto attacks, is taken for granted, but is designed in a way which creates a closer to linear power growth. AP, is designed in a way which causes power growth closer to exponential, due to it scaling generally better than 1:1 with abilities.

However RIOT, you've decided that AD shouldn't be limited by linear power growth, and should instead should have just as fast of growth as AP does.

This is why AP fighters are consistently weak (they always end up assassins or tanks), this is why AD casters are consistently oppressive, and this is why snowballing has become rampant in your game.

I don't like giving ultamatums, but there really are only 3 doors in this room.

1. Rework how the fundamental stats of the game work, pretty much admitting that the philosophy has changed to such an extreme extent that you need to reformat the game.
2. Change AP itemization in an extreme way, which creates a more natural scaling for the stat, basically find a way give AP what AD has, because you've done the opposite already.
3. Back track, make AD champions universally less dependent on abilities (including all of the AD casters), and more dependent on auto attacking again. Basically, exit through the door you entered.

1.5) Make a new game, with the new format that you need for this philosophy, and find another team which are better at designing in the current format.