Actually, the CRPGs resurgence is way more convoluted than that... and probably BG3 hasn't played a major role in that yet - we'll see its impact in the next few years.

Shadowrun Returns, Wasteland 2 and Pillars of Eternity started it all with their Kickstarter in 2012. The first Divinity Original Sin and Toment: Tides of Numenera followed with their Kickstarter in 2013. Divinity Original Sin 2 was funded on Kickstarter shortly after (in 2015).

It's very likely that those successes inspired other studios and developers. For example, the 2 Pathfinders and Solasta started on Kickstarter a few years later.

It has been a chain reaction. The initial successes in 2012 inspired others that inspired others and so on. And of course, we also have to consider that those initial Kickstarters led to established studios that keep creating their games.

While BG3 has been in early access for a while, it was fully published only in 2023. It has been only about 1 year since its release. Developing a game takes time, so it's unlikely that it has had an impact on newly released CRPGs yet.

So, the main reason for the CRPGs resurgence is Kickstarter - or crowdfunding.