I mean....being able to initiate combat with enemies on your own terms isn't exactly new. This isn't really an innovation in the genre, so I have a hard time thinking that it's the reason for Larian's success. But you do point out something else: Multiplayer. Most cRPGs are designed as single player experiences. I haven't played multiplayer yet, but everything is more fun with friends (and it's likely more challenging, too.)
I wonder what the stats are for how many people are playing multiplayer. Becuase this sort of goes back to what I said before, about the allocation of resources. If other designers conclude that multiplayer is the route to take, and the single-player experience suffers as a result, I'd be pretty sad about that.
It is already suffering in BG3. The party/inventory system is the way it is because that is Larian's design philosophy for co-op play.
