Well, since a lot of Larian's expansion was connected to cinematics, they might as well expand upon it. BG3 won't be much copied by anybody though, and I'm not sure whether Larian will do it themselves (in particular in terms of scope and campaign length). It's too open for that due to its systemic nature, how there's so many permutations running throughout quite a lengthy game (Mass Effect et all are significantly shorter). That's why I voted "extravagant". Not because I dislike it despite my preferences. But because that's literally what it is. It's insane in a way that no other major studio would greenlight, as there's so much stuff happening in an expensive cinematic way that you may never ever see (and hear) even upon multiple playthroughs. Big studios don't work like that. They and their investors want to make damn sure that you eventually see where all that money went. Which is also reasonable, from a budgeting point of view for themselves. Of course, being reasonable was the last thing Larian had on their agenda. And they could afford it, as their CEO is a crazy guy himself fully going along to it.

BG3 really is quite a mix of two very distinct schools of design sort of opposed to each other in a way. The one is those also
shared by Immersive Sims (which work little with cutscenes to begin with for reason), handing you tools, a world with system simulations (AI, physics, sound, lines of sight, lighting, etc.) and problems to overcome in whichever way you may see fit. The other is the Bioware-like school (also adopted by CD Projekt) that sees games as sort of like movies. Not seldom are you cast as a fixed protagonist, or with a more finite choice of main protagonist to begin with. The plot is also typically more linear, also how it progresses from start to finish -- you can't say, skip entire areas/sections outright in Kotor / ME or Witcher, whereas in BG3 you can advance pretty early to the next area if so you wish. And the decisions impacting narrative beats however minor aren't quite as moment by moment as here, but typically connected to a handful of major ones, from which the plot diverges some (like a Chose Your Own Adventure Book).
People have already expressed that in the final act of the game BG3's reactivity would come crashing down some. I'm not there quite yet. But that wouldn't surprise me. What suprises me is rather how they could keep that up for two acts, or rather dozens of hours of playtime. We're talking quests that can borderline be sequence broken and the game not glitching out, be tackled in any one order, with different party compositions, different main characters, NPCs being able to flat out die early game (to not even appear later on when they could), spell and player actions in general leading to permutations likewise (such as the aforementioned instance where I had cast disguise on my char, for a sequence to play out completely differently), etc. etc. And the dialogue/cinematics playing out accordingly. Even considering shortcuts being made, such as animations being recycled, that's massive.
It's not merely about the VO and motion capturing animations. It's also about bug testing. That must have been a nightmare, and in retrospect I may have actually encountered one myself recent (not actually sure). Had Larian additionally provided fully VO (or rather, VOs given the options available) for the main character, they'd probably still be in EA by summer of 2024 (kidding).

Curious about their announcement of what's next. I'll say a shorter (not necessarily "lesser") project roughly in the vein of BG3 (cinematics included) -- plus Fallen Heroes getting revived, the Divinity tactical game that was put on hold. Studio's too big to work but on one game now and a more "focused" tactical game as well as a shorter campaign game would fit the expressed desire in interviews of doing something a bit "smaller" next.
That way, they'd also avoid what CD Projekt had done after their own big break: Growing even more in a short amount of time for an even bigger and more ambitious project, and getting some burnt for it. As argued, it seems Larian have realized that they've reached a limit here. Crazy dudes or not.