I can say magic missile is not at all a must because I've not used it once on my sorc.
In any case, I don't think the aim of DnD is to have all spells be equally useful.
If you think fights don't last long enough for you to be able to get value out of defensive or buff spells, I have to imagine you're not playing on tactician. Because fights can definitely take a long time and often do. A twinned haste in one of these long, hard fights. I've also found sanctuary to be very clutch when someone is on the verge of the death. And then while I don't cast bless there is a ring that gives bless when you heal someone, which is nice when paired with AoE/multitarget heals.
After act 1 I wasn't even able to play on balanced lol. Well I could have maybe, but then the reloading would have become so tedious it would ruin the experience for me. Balanced felt like tactician, and the high difficulty actually shortened the fights, as I was downed before I had much chance to fight back. Didn't know my sorcerer could cast twinned haste lol, I could have used that I guess
Oh, bummer. Yeah, twinned casting haste is nice. For spells like fireball you have to use the quickened spell to use them as a bonus action. If you have haste, that's like 3 fireballs or whatever other spells you want to use in a turn.
For me, I think I only played like 2 or 3 fights on balanced - mainly fights where there are allied/neutral NPCs I wanted to keep alive. I probably could've kept them alive on tactician if I was willing to redo the fight a few times, but I I just put it to balanced for the sake of time.
