Thats why my system locks spells behind proficiency and expertise requirements.
The 5e Wizard has the big problem that, no matter what subclass you pick, any wizard player will pick the same 90% of spells and only like 10% of unique spells that fit that subclass. The base wizard class is so powerful, that, outside of a bladersinger, all the subclasses don't have enough power budget to make a wizard feel distinct. Abjuration Wizard, Necromancer, Divine- they all will run around with Mage Armor, Magic Missle, Fireball, detect magic, identify ... the spelllist makes the wizard. But because every wizard can pick every wizard spell, always the best 10 spells are picked.
But what if you make proficiency and expertise in a school of magic a necessity for being able to learn higher level spells of that school.
Like, a fireball can only be learned by a wizard who has expertise in evocation. Mage Armor and Shield require proficiency in abjuration.
Now wizards are distinct!
A necromancer will mainly pick necromancy spells, an abjurer abjuration spells and so on. You specialise in one or two schools of magic.
Of course we would need way more spells to bolster the arsenal. We would also turn certain subclass features into spells - which would allow us to get 8 subclasses for the page count of one:
At 1 level, pick two proficiencies for magic schools. At 3rd level pick an expertise for a magic school you are proficient in. Later class features build on top of that.
We lean into the "the spell list is the wizard" thing that is already happening and turning it into a feature instead of a bug.