BG3 is genuinely the best video game I’ve ever played and I’ve played like… quite a few of them over 20+ years. A combination of lightning in a bottle and just genuine hard work.
At the same time, I think the story is very much over. They’ve tied a ribbon on it and I really feel like further “expansions” could only make it feel more murky.
As for BG4, this one took about two decades to come out, so I can’t really say how I’ll feel either way in 2050.