Mesh processing is a very difficult research domain in computer graphics that has been iterated for several decades, and we still don't have a good automated solution for retopology (Partly because the problem is hard to define in a mathematical way, but also since it's not a problem you can just solve with AI by throwing data and compute at it)
It's a novel approach and worked well in BIM a few years ago, though not anything real-time.
1. extract even a super approximate (meaning, like square edges, with some visual details) mesh from gen ai or a scan as a starting point,
2. move things around and define volumes for gameplay needs,
3. name things ("this is a Victorian house in a surprisingly good condition compared to the neighborhood it's in"), have human guided gen ai polish the things a bit more from the labels within the bounds of the gameplay required volumes,
4. let run time dlss fix the lighting etc from the rough geometry
Gaussian splats are definitely interesting and do something things older tech is not very good at, but at the same time, it's definitely going to end up being a tool in the tool chest and not completely murderating mesh-based tech or something because they have a lot of other weaknesses, like editability. Or dynamic animation.
What I think some people may not realize is, that's not particularly uncommon. There's a really, really long line of graphical techs that do something particularly well but their weaknesses have kept them in a limited use. It's not a problem for Gaussian splats to become a tool in the toolchest; they aren't a "failure" if we're still using meshes for a lot of things in 10 years.
Mesh-type techs are the "default" for some good reasons.