One of the most common complaints I hear about Bg1 and 2 when people go back to play it is that it "hasn't aged well and it feels like work to play it".
People will say that about BG3 in 20 years... if its lucky. Probably they will just ignore it though. That doesn't mean that I think it will be bad. I have enjoyed my time playing it. Its just that most games don't stick around that long, and I doubt this one will be much different.
Baldur's Gate 1 and 2 still have people going back to them in spite of the fact that they "haven't aged well", and I hear that they also have a sequel in the works.