If in BG3, you were ONLY in control of your own character, I actually wouldn't mind it being completely Turn Based. But I LOATHE having to micromanage more than 1 character each turn.
It's a party-based RPG. you play the whole party.
I can't imagine playing the original BG without controlling all the characters, and I (pretty loudly) criticized later BioWare games when they started to take that option away (NWN gave direct control over only the main character - KotOR let you control any character, but only one at a time - same with Jade Empire - DA:O gave back full party control - DA2 returned to the KotOR design, but compensated with the best customizable AI system I've ever seen - DA:I eliminated that AI control system - and the ME games aren't even really RPGs).