It seems to me that there's some overheated rhetoric that reminds me of the tech-specific spin on the Appeal to Novelty fallacy [1], where people think a new tech is going to uniformly improve on an old tech, that if it isn't an improvement on every front it is somehow a "failure", and therefore if we like the new tech and we are on Team New Tech that we must defend how the new tech is an improvement on every aspect.
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.