Larian are quite capable of making the game any way they want, but from what they have said it's clear that WoTC liked the TB/MP mechanics of their latest D:OS games for its similarity to PnP, so that's the basis of their agreement for BG3.
This is great if you want to play the game as a PnP experience with friends, but not so great if you want to play a SP RPG experience where you invest yourself primarily in your own character.
From the gameplay so far, it doesn't seem that your companions can do anything for themselves apart from follow you ( no AI that I noticed ), so you have to control every action. At the same time, you have apparently tense conversations with them at camp, because they are all "individuals" with their own motivations - apparently just not enough motivation to actually do anything for themselves.
That's not to say there are no players that will be happy to play SP the way Swen is showing the game; I might even like it myself, I don't know yet - it might be fun, or it might be very tedious; so it would be nice if companions were actually capable of doing their own thing in SP, if you want them to.
The requirement for MP to work the way it does, also means that the game has no real concept of passing time, since some players can be acting in "real-time" while others are in local "turn-time" bubbles. This makes it very difficult to implement something like a day/night cycle. It's not clear how Larian will even deal with the 7 day ceremorphosis, so I suspect it will either be tied to events, or to the number of times you use long rest, rather than any relation to how long you actually play the game.
As for the companions; they are currently a rather limited choice, both in class, and in outlook, seemingly designed as a ready-made co-op party. I've no real interest in playing *AS* a pre-made companion, but it seems you can ignore playing *WITH* them if you don't like them, at the cost of using generic hirelings with no particular personality. Swen also held open the possibility of more companions in one interview, but that probably depends on whether they can afford that or not; it's not guaranteed at all.
As you suggest, posters like Kanisatha and myself do actually want the game to be good/enjoyable ( or we wouldn't waste our time in the forum ), but don't see the sort of video game we each prefer reflected in BG3. Just as some Fallout 1/2 fans were unhappy with Fallout 3 because the gameplay was totally different, even if the lore was mostly respected, there are people who enjoyed BG1/2 that don't see BG3 as being the same sort of game, with the features we enjoyed.
I'm quite used to games in series changing and being grumpy about the changes, but most of the time you don't get to express your views until after a new game has shipped, by which time it is too late. At least here we can let Larian know that some of their potential BG3 customers are looking for differences from the experience than they are proposing. The more concerns they choose to address, the wider their sales base will be. Clearly there will be some concerns that are cost-effective to address, and others that are not; it's their choice what they do.
Personally I’m not bothered about it being like the tabletop, and I’ll almost certainly be playing alone. I like some turn based games because when done well they can be much more tactical than real time games. I’m in full control and I can plan what everyone is doing. It’s just a different way to play. No reason you can’t enjoy both chess and football.
Interesting point about your party being individuals though. I’ve never really felt that characters following their AI scripts had anything to do with their personality. If they do something daft, it always seems like it’s the program at fault, which I sometimes find frustrating.
If someone managed to nail the AI well enough that it really seemed like the actual characters making mistakes or not listening to me, I’d definitely give that game a go.
But just because Larian is doing an early access doesn’t mean they will be willing to change anything fundamental to the game. Sorry, but there just won’t be real time combat. They have a clear structure to the game which they’ve worked hard at to get to this point. Even if by some remote chance they were willing to try the sweeping changes that some want, the result would almost certainly be a total mess.
