Mana changes are bad because zed doesnt have to use mana

Champions are different. Zed exists and is supposed to have an edge during lane phase. ban him and move on if you can't deal with the idea of someone else not needing to buy mana like you do.

Inb4 'yasuo/katarina/akali/etc doesnt use mana either'. There are a handful of champions who are designed with the specific strength of not using mana as part of their kit. They are balanced around their lack of mana. That doesn't mean the entire mana/regen system has to account for a few champions existing to appeal to your sense of 'fairness'.