I think it could be very interesting to play in such a game/world.
I would say that if one were to try a system like this out, first thing is spell progression tables go in the trash!
No more "2/3, 3/2/1, 4/3/3/2" or such like. You have your cantrips and, like, 2 spells you can do -at will- from first level. Learning new magics to make is a LOT slower and more complicated. Someone who could work, like, 5 different spells in a single day would be a notable/feared/awe-inspiring magic worker.
Magic-users become more about "how can I change this one (two) thing(s) I have figured out/know/learned how to do? [or just woke up able to do and I don't know why. Now I'm a 'sorcerer.'] How can I use this in a different/new/creative way [ideally, a way that benefits the party during adventure]?"
Meta-magics, for lack of a better term -or a jumping off point, would become more tied to your progression. Different alterations of previously specific spell descriptions become much more important. e.g: take your Shield spell and turn it horizontal to carry stuff in... extend/increase it into a full "dome" forceshield with a 10' radius... a few levels later, use your 5' diameter shield turned horizontal as a "hover board" that allows 50'/rd movement... etc...
It'll take a lot more work and/or "buy in" and/or rulings from the DM as to what is permissible/makes sense.
Intelligence checks, maybe, to use your spell in a different/new way...or some kind of mechanic for what some Superhero rpgs term as a "Power Stunt."
And learning additional spells becomes a lengthy process. No more "finding someone else's spellbook and transcribing things for tomorrow." More like, "Finding someone else's spellbook and working at it for a few weeks or months to figure out ONE additional magic manifestation you didn't know before." I'd say additional spells, and new tiers of spells, would be no more than every...let's say, additional 1st or 2nd tier spell at 4th level. 1st-3rd tier spell at 7th. 1st-4th tier spells at 11th... yeah, that could work.
There's definitely a way to make it work...could be fun/interesting.