Stuck in the 90s
I actually wouldn't know about the AI using spells, I always micromanage in games like that, be it pause or turn-based. I do see it as at least relevant, because regardless of when your spells come back, you're still dealing with constraints, and still dealing with rounds of nothing but basic attacks - at least with D&D, there are at-will cantrips. PoE2 didn't even have that while at least anything resembling 5e would. For me, I've had a ton more fun with turn-based combat since Divinity: Original Sin than I ever did with pause-based RPGS (like BG2), but I'd never want to encourage a company to only make turn-based, for those who prefer closer to live-action - thus my vote for both!PoE2 changed the spell system from the original PoE to all spells refreshing after each combat, so it wasn't a problem if the AI burned through spells in an encounter.
The original PoE had spells recover on a (long) rest like D&D, and there real time with AI was an issue - either you let the AI use them and would burn through them quickly, or you didn't in which case it was effectively turn based as you be pausing often to cast.
So PoE2 isn't a great analog for D&D combat where there's a lot of long rest recovery spells and class features. The original PoE was closer, and that did have issues with real time because of AI use of them.