There seems to be an uncomfortably large nuber of people coalescing around the idea that the goals of BG3 are wrong. That taking 5E as a base and tuning it to make something that would appeal to fans of Divinity Original Sin and tactical combat is just fundamentally something that shouldn't even be attempted. BG3 needs to be a strict interpretation of 5E and nothing else is acceptablr. Solasta did it and it appealed to a tiny number of existing fans of 5E so that's evidence it's the only possible solution.
If that's true (and honestly I can see the logic) it's still not useful feedback. Larian are all in on BG3 they simply cannot pivot it to being a niche product aimed solely at 5E purists. Nor can they ditch the 5E system at this juncture. BG3 is going to be a game based around giving each player several interesting choices every turn and minimising those turns in which a player rolls a dice, misses and nothing happens. They're not going to change that based on what people on the forum say. It's reasonable to be upset about this, it's not reasonable to expect this to change.
"purist"
I'm pretty sure there's a lot of people who think the current combat design is fundamentally broken, and their reasoning has nothing to do with adhering to tabletop DnD or 5E. Or is wanting Larian to dial back a massive accuracy bonus or penalty based on a difference of a few pixels worth of positioning a '5E purist' concern? Or the exploitable time bubble stuff where you can send in one party member to initiate combat and then sit on their turn as the rest of the party freely sneaks into the fight as long as they don't wander into enemy sight cones?
If there really is a '5E purist' concern, it'd revolve around the lack of controllable reactions and ready actions, which make up a huge chunk of combat that they claim this game is an adaptation of. And quite frankly, I don't understand why people are hoping this game ends up serving as a template for future DnD games in its current state, when we're missing such fundamental features.