Seems weird to me that Solasta has so much invested in getting 5e right but not have multiplayer implemented. Single player D&D just feels odd to me, like you have strayed so far from what D&D is meant to be - can it still be considered D&D at this point?
Aren't BG1&2 (arguably the best D&D video games) considered excellent single-player experiences? There's nothing that requires a D&D game to be multiplayer.
Obviously it'd be incredible if Solasta was multiplayer, and even better if a DM could control monsters directly instead of them acting on their AI. But that's simply too much work for their 12-developer studio. Hopefully Tactical Adventure's next game will include multiplayer.
I get it, different value systems, no big deal. For myself I go with Dan Harmon's (Community, Rick and Morty) definition of D&D from Harmontown where he defines it as "a story we tell together".
For some people D&D is an outlet for artistic expression, vis a vis storytelling. These people are my community, the storytellers, the jokers the ones who act out all kinds of crazy stuff. The beauty of the BG3 system is that it is being BUILT around a solid foundation that supports my form of experiencing D&D in addition to how you want to.