The bar is so high now, that both Larian's next game, and Baldur's Gate 4 will really struggle to match it. They will both live in the massive, overwhelming shadow of BG3 and hopefully can succeed despite that.
Yeah I'm skeptical that they will, but one lives in hope.
BG4 I strongly suspect will end up being developed either by a studio which just doesn't have the talent and vision necessary, because WotC have such weird and stupid ideas about picking studios for this kind of thing (plus they literally fired everyone who picked Larian lol) and will inevitably greedily want a much larger cut than the 5-10% (I think we heard 8% specifically from one source, but I forget where) of gross revenue that they seemingly got on BG3, so will be unable to work with "real" studios. At absolute best, it'll be basically a faithful recreation of 5E D&D gameplay, with an uninspired and trite plot and characters. People will defend it aggressively, because people do, if you get the rules mostly right. Just look at how defensive people are about the Solasta campaign or the built-in NWN campaign, both of which were absolutely terrible, like embarrassingly bad (particularly NWN - how the hell did the people who did good with both earlier and later projects screw this one up so bad? It's like a child wrote it! And not smart or imaginative one!).
Larian I think will probably make a pretty cool CRPG, but the issue is Swen also has some pretty bad ideas, specifically:
1) He likes precisely one flavour of fantasy setting. Super grimdark, but with lots of jokes. Now, if he lets the writers run the show, I think he'll be fine, but I also think he'll be pushing pretty hard for "jokey grimdark" of the worst kind, and I don't think audiences are going to respond as well to that as they did to BG3 (which to be clear, is about 10% as grim as DOS2 was). I think what they'll get is millions of sales and millions of people quitting pretty early on and then having a negative attitude to Larian.
2) Whilst he has good "big picture" skills about like, how interactive the world should be and so on, Swen has no idea what good gameplay design actually looks like. He thinks entire screens full of hellfire and explosions are what "cool combat" looks like. He thought the combat and advancement designs in DOS2, which are essentially trash that they got away with because of other factors, were stellar. Certainly prior to BG3's launch, he had no comprehension whatsoever of the rather obvious-seeming fact that part of why BG3 was going to succeed was that, frankly, D&D 5E's mechanics are much better, and much more accessible and generally friendly to non-hardcore gamers than DOS2's were. That being forced to use those is part of why BG3 was an insane success. It combined the best aspects of DOS2 (the hyper-interactive world, for example) with much better combat and a much better setting.
So I worry. I think Swen is a blessing and curse. A blessing in that he will almost certainly prevent Larian from being bought or "going corporate" in any way, but a curse in that whilst he is clearly a lot of fun, his "taste level" is basically non-existent.
My feeling is his wisdom will win out, and he'll let the designers/writers make the big decisions rather than insisting on grimdark screen-fire-fests, but there still remains a potential issue:
3) Not making a CRPG and then being shocked when nobody buys it.
I think this is a more minor risk unless Larian pours huge amounts of money/effort into it, but I do think there's a possibility Larian will decide to make a non-CRPG as their next game, and assume that, because it's them, and because they think the game is great, they're going to get near-BG3 levels of sales. And they won't. If they make a tactical RPG or fantasy X-Com-ish deal or the like (as they've sort of hinted they might), they'll get decent sales, but it'll be a fraction of BG3.