No, I don't thing that BG3 is a huge imporvement over DOS2 (which I find average, by the way). Mostly because DOS2 was it's own thing and here we have an abomination which doesn't know what it is.
And even if BG3 was a great leap from DOS2, this wouldn't be a good thing. BG3 should be it's own thing, I think, not an improvement of another series. Like let's say Dragon Age should not be an improvement of Mass Effect. Annoyances/Complaints aside.