I’m feeling a bit torn myself. I understand the thinking behind the vanilla rules; it helps balance out some of the spellcasters’ power, especially at higher levels. But my understanding of balance in 5e is that it’s to balance the players against each other, to avoid having 1 or 2 players be so clearly better at so much that it naturally pulls the limelight away from the rest of the party and causes people to lose interest their own character.
I think totally unrestricted spellcasting carries the potential for imbalance, but doesn’t guarantee that outcome, and if I’m not making my spellcasters manage their resources then I’m doing something wrong. Something like Matt Mercer’s house rule “spells of 2nd level or lower” would also be a good compromise because it allows the utility of things like Misty Step, or for a Gish to summon a shadow blade etc.
What do y’all do at your tables, and why?
True, although I feel like requiring proper resource management would encourage the same sort of creativity. Maybe you want to keep that 3rd level spell slot available in case you need a counterspell, or to cast Fly for exploration later on