D:0S2 worked because it was its own system, based in its own world with its own lore, and with its own rule-set - which was clearly explained due to how simplistic its various 'moving parts' were. It was flashy, but ultimately shallow, and that worked very well for it as a game.
BG3 has none of those fail-safe elements - It's based in someone else's world and lore space, which is a major point for disappoint or annoying a prospective audience, and it's using an existing and established rule-set, which the current game does NOT do a very clear job of explaining ,and does not communicate consistently at all... and which Larian are further deviating from heavily, in many unnecessary ways, beyond the reasonable to-video-game translation QoL adaptations, and that's another big point upon which they can skewer themselves annoying or disappoint audiences, when their advertising and draw cards were to set themselves up as the definitive 5e video game. They are also responsible for this entry as being a continuation of an existing and much beloved franchise, and are using that as another of their major draw cards for pulling crowds... so if the game doesn't feel like a true successor to those games, that's another place where they can hang themselves disappointing or annoying prospective fans. These are all considerations that they didn't have to think about with their earlier games, and while they've shown a great willingness to ride the coattail benefits of these things, they haven't shown the respect they need to for utilising them, and it could end up going very badly for them as a result.
They could make a very excellent game that could stand comfortably and be popular on its own, if it were its own system and based in its own world, with its own lore, like the Divinity games were... and yet still end up with a complete flop and the ridicule of the greater gaming community instead, for pitching it as something that they didn't actually deliver on and never intended to - or being seen to have done so. This isn't meant as an attack - it's just a genuine risk they should be more wary of, with the project they've taken on.
One thing is for sure, BG3 made in Larian style makes sense. Put yourself at WotC position : you have a franchise which hasn't had a game in 22 years, its fan base as dwindled to basically a drop of water in the sea of modern player base, and its genre has also became so niche that it is a miracle that you get one good game per year. Would you rather risking a lot of time and money on trying to chase that past or would you let the most popular developer by far in this domain take a stab at it?
