Larian Studios may be the ones who are developing Baldur's Gate 3 but they weren't the only ones interested in it. Obisdian Entertainment and inXile Entertainment were both gunning for the license along with Divinity: Original Sin's devs.
Baldur's Gate has been a hot topic when it comes to licensing a game to develop apparently. Obsidian Entertainment, inXile Entertainment and Larian Studios have all been trying to score the license for an entire decade apparently.
Classic RPG (CRPG) fans can be found all over the world and in all corners of every industry, especially the gaming one. Brian Fargo, Feargus Urquhart and Swen Vincke are three such enthusiasts and they all happened to be the heads of their respective studios.
Apparently, Fargo was really close to acquiring the license at some point in time but his hopes were cut short due to Atari getting into trouble.
Feargus Urquhart also attempted to acquire the license for Obsidian Entertainment and Fargo seems to have believed his peer would pull it off due to a better inside track.
Larian Studios' CEO Swen Vincke was gunning for the license alongside them and would eventually get it since Larian officially announced the game's development but it wasn't an easy journey and it also took him several long years.
Interestingly enough, both Obsidian and inXile have recently been acquired by Microsoft with Larian remaining the only independent studio. It is hard to imagine this had anything to do with Forgotten Realms' decision to pass the license to Larian though, since the acquisitions happened only recently, not ten or more years ago.
While Baldur's Gate 3 license went to Larian in the end, Obsidian and inXile are both working on wrapping up their RPGs that have high chances of being successful releases - The Outer Worlds and Wasteland 3, respectively.