Why Was So Much Scaling Removed From The Game?

So over the years riot's balance team has removed the amount of ability power you can stack along with some ad item's effects and replaced them with base damages.I can't really understand why riot chose that course for the game,the choices the player can make are becoming fewer and fewer every season with this season's giant step of introducing the new rune system which furtherly limits the player's choices. Now pro players told riot that the support item build path with actives are useless and that they should be removed from the game and riot of course listened. What brought players to league of legends and not other dota 1 spin offs were the fact that the player had more choices and that his choices mattered,as dota 2 and other mobas added ability power scaling into their game,becoming more like league of legends,league of legends became less like league of legends taking away scaling and choices from the game.