Even if Larian insists on their innovations, it would be nice if there were an optional D&D 5e mode, especially in light of it supposedly being a D&D 5e based game.
Such a thing might require a mod at this point, actually. Which would be fine, if someone who knows the technical aspects of the game's coding could get things up and running relatively quickly. Stuff like tweaking high ground/low ground, backstab advantage, enemy AC/HP and the bonus actions would likely be possible. Adding in stuff like player-controlled reactions and the dodge action would be far more complicated since the proper coding framework for them probably doesn't exist yet, however.
Something like this happened in the D:OS2 community, with them creating a mod that was borne out of the grievances people had with the armor system called Divinity Unleashed. It ended up being way better balanced in the end since it was really a comprehensive rebalancing mod. The main feature was that it changed armor from essentially being an extended health bar that protected you from status effects into a damage reduction system, so while it did result in status effect spam like the first game, status effects were also rebalanced and it made utility battlemage builds viable all the way to endgame. It also adjusted spells like Bless to be far more usable, meaning blessed surfaces were now far more practical to utilize.
Experiencing how the changes from that mod impacted the experience for myself is part of the reason why my arguments in regards to BG3 are the way they are, even if I never actually did finish a full playthrough with the mod since I had basically played through the game like 5 times at that point and BG3/Solasta/Pathfinder: WotR had begun taking all of my attention by then. It was also starting to get difficult enough that I had to accept that I wasn't nearly as good at the game in terms of using conventional strategies as I thought I was, rather than abusing certain things that were overpowered in the vanilla version.
Ideally we shouldn't need a mod to begin with, but it is always a fallback option if some kind soul out there with enough time on their hands decides on that undertaking.