So Anivia's waveclear is too good?

Meanwhile Heimerdinger places 3 turrets and gets free waveclear all game (until someone destroys the turrets at least). In fact, all he has to is stand near them and he gets free harass/damage. Meanwhile Anivia needs to spend a f*ckton of mana every second her ult is up. Please tell me, when was the last time you saw Heimerdinger get mana regen (and no Morellonomicon doesn't count, because literally every mage in this game buys that item)? Anivia has a strong kit, I won't deny this. But her waveclear is definitely NOT the problem.