Early Access is more likely to benefit the producer than the player himself. Every developer should employ testers in the quality control department. It is not a pleasant job, because sometimes it comes down to simply clicking for hours on the menu to see if something is breaking. Playing the game from start to finish is also not the perfect method of finding and reporting bugs when it comes to cRPG. Lots of skills, spells, items, dialogue, scripts that push tasks forward in different ways - 10 players can have 10 different bugs and it is impossible to check every possible option.
And Larian himself definitely has no shortage of funds to complete the game, and Early Access is the only way to communicate effectively with players and their expectations.
I hope that the team from Haemimont Games will also take advantage of this opportunity 🙂