Since when it comes to making updates to parts of the game, they can go on for literally years and years making lots of adjustments to make the game as perfect as possible (As we saw with Act 1 in EA, 3 years of taking on feedback and making updates to that singular Act). At some point they have to decide enough is enough, especially given that these updates don't earn them any money as they're released for free. Meaning even if they DID want to perfect the game with updates they'd eventually be forced to stop in order to work on projects that will generate revenue.
When it comes to it, I find it hard to fault Larian for stopping when they did. In my mind it's a miracle that they went as far as they did post-release. It's not often developers bother to patch things post-release and rarer still to have multiple patches.
I know CD Project Red did many, many updates with Witcher 3, and even updating the oldest Witcher games recently. It is a business strategy, as it will put the game company in a very good light, making it easier to sell future games. "See how much they care, we will be sure to get a good product from them. If not now then eventually." Also the massive comeback on Cyberpunk. Seeing it in comparison, I think Larian may do themselves a disservice by stopping now when they have so many things unfinished and unpolished in BG3. But ofcourse I just want more of a good game, so easy for me to say.
