I actually had good luck with the game close to release, it had bugs but it didn't crash. It was also stable when I played Phantom Liberty, with patch 2.1. 18 months ago.
I haven't played the game in a year, and I wanted to see the new features they added with 2.2 and 2.3 patches, but it seems with new developers come new issues. (as you know 2.2 and 2.3 wasn't done by CDPR).
I'm not even OC-ing at this point, so it can't be that.
Phantom Liberty is well worth the time, it is a much tighter experience than the base game, more focused and linear. The DLC itself has multiple different endings, and it can even add a new ending for the base game.