It's actually a good thing that the items are more unique and are defined by their utility

Rather than before where it was a good cost efficient stat stick item that happened to have a zhonyas' active. It should have been that you get that item FOR that active rather than getting it because of the eliminating preliminary weaknesses such as Mana regen and CDR while giving a good chunk of AP/defense.

the items should be bought FOR their active and the gameplay it provides, not because that item gives all these good passive stats with the active is a little cherry on the top.

Deathcap should be the #1 item if all you want is pure damage.

however if this is the design paradgrim you want:

Every mage needs a buff in usability, namely mana pool per level gain, Reducing or removing certain cast times, and mana cost reductions across the board.

Or deathcap should give a shit ton more AP.