So Mana users get 40-50 mana in compensation from the removal of Mana Pots
So with the removal of Mana Potions, Riot has decided to give most mana users 40-50 mana in compensation from the removal.
I personally think it is a good idea to remove the mana pot, but we didn't buy it because we needed more starting mana. We bought it because our champion was really mana hungry. Yes it's a little buff, but 40-50 mana is usually around the cost of one spell. I personally think you should increase the base mana regen of mid champions as well, and not only supports, because there is nothing worse than losing lane against a Zed or Yasuo because you have mana and they don't. 40-50 mana is not going to do it...
TLDR: A little more mana sustain, not just flat mana