Baldur's Gate 1 & 2 as well as Divinity: Original Sin 2 were all huge successes and Baldur's Gate 3 was in early access for 3 years to either test it or read testers opinions. So you've got a very successful IP using a renown system, a devoted studio known for quality games with proper resources and their own, capable and proven game engine, years of polishing the game and adhering to fans feedback. If you "completely understand why it wasn't on the radar" then... I guess you could get a job at Microsoft.
Everyone knew BG3 would "a success," but it hasn't just been a success, it's been a nuclear bomb of a success.
Optimistically, people were expecting to get around 1 million in sales. Total. THAT would have been a GREAT SUCCESS. Today I think it has around 10 million on Steam alone, 10x the "hope we get there" number.
Imagine taking a job and hoping for a $10,000 bonus for good performance, and then your boss drops $100,000 on your desk. It's that level of joyful shock.
Estimates for Steam is roughly 4.9 million sales. That data comes from peak players, average weekly players, and achievement tracking information.
Estimates taken this way usually skew higher than they really are, but the data for the current active and peak player estimates look good. As they have dropped to a quarter of weekly players.
DOS2 has sold 5M copies over the life of it. BG3 has sold nearly 10M in the first month on steam alone. Probably close to 30M over the life of the game.
It's several orders of magnitude more successful and easily the most successful CRPG ever. You all really are missing the scale.
They could have predicted more success than they probably did but I don't get why your comment has so many downvotes, Larian itself prepared for 100k players at launch too, not over 800k so no one really predicted how much of a bomb this game would be!