Baldur's Gate 3 studio CEO says that if he couldn't make a D&D game, Fallout and Ultima were the only other RPG licenses he would have considered instead : "There was not a lot to choose from"
...
"It's one of those IPs that you know a lot of people will want to work on. So it would be great for attracting other people to the studio," explains Vincke of his reasoning at the time. "I felt like there was a glass ceiling that we wouldn't be able to break through unless we had triple-A production values, budget, marketing, all the triple A things.
Elsewhere in the interview, Vincke discussed the impact of those production values, and how they fitted into the game's pipeline, particularly when it came to cinematics. "From where I was sitting, coming back to my strategic vision for Larian, [cinematics] made perfect sense. If we were going to bring a game like Original Sin 2 to larger crowds, we would need to have triple-A production values, whatever that takes. Because it's only then that we're going to discover if there's a market for this type of game."