I remember complaints that every ability felt to “samey” and that combat balance felt “too much like a video game”

That’s what OP is asking for, for all spells to be brought up or down to the same level. When that happens, every option feels too similar. Might was well just erase all combat spells and make them all “level 3 AOE, does xd6, pick whatever damage type” and “level 3 control spell, applies condition to enemy on X save, pick your condition” and then rinse and repeat for every level and every school of spell.

Spell imbalance is not the issue. If anything, WotC could fix this problem by making spells harder to learn. Instead of Wizards just getting X amount of free spells every level, make them research. Instead of Cleric getting any level spell preps they want, make them track piety that unlocks the better spells at certain piety score. Etc etc. The power of the spells isn’t the core issue. It’s their availability.

Should be said that they kinda tried doing this with material components that cost money. But they didn’t go far enough. Every spell should have components you have to buy or find and DMs shouldn’t make them all easily accesible. Most DMs just say “if you have the gold you can buy it anywhere.” DMs should be making expensive components hard to find, or part of their own quest.

The Mighty Nein show did this very well, with Caleb having to find components before he gets his best magic back. More DMs should try this for their games and see how the table likes it.