its a choice of class, but, sure, everyone chooses to MC or not, every level.
TBF, 6 of those choices are made by all classes.
The Wizard chooses 2 skills, subclass, 3 feats (those 6 like everyone else), 5 cantrips and 30 spells, over the same 13 levels.
And, there are, as already mentioned, a lot more spells to choose from than feats and skills, combined.
And, skills, expertise, and ASIs are just numbers, they make you better at things anyone could try, while spells can give you entirely new things to do.