Are meshes not used instead of gaussian splats only due to robustness reasons? I.e., if there were a piece of software that could reliably turn a colored point cloud into a textured mesh, would that be preferable?
Photogrammetry has been around for a long time now. It uses pretty much the same inputs to create meshes from a collection of images of a scene.
It works well for what it does. But, it's mostly only effective for opaque, diffuse, solid surfaces. It can't handle transparency, reflection or "fuzz". Capturing material response is possible, but requires expensive setups.
It’s not only for robustness. Splats are volumetric and don’t have topology constraints, and both of those things are desirable. The volume capability is sometimes used for volume effects like fog and clouds, but it also gives splats a very graceful way to handle high frequency geometry - higher frequency detail than the capture resolution - that mesh photogrammetry can’t handle (hair, fur, grass, foliage, cloth, etc.). It depends entirely on the resolution of the capture, of course. I’m not saying meshes can’t be used to model hair or other fine details, they can obviously, but in practice you will never get a decent mesh out of, say, iPhone headshots, while splats will work and capture hair pretty well. There are hair-specific capture methods that are decent, but no general mesh capture methods that’ll do hair and foliage and helicopters and buildings.
BTW I believe there is software that can turn point clouds into textured meshes reliably; multiple techniques even, depending on what your goals are.
Not everything can be represented by textured meshes used in traditional photogrammetry (think Google Street View)
This includes sparse areas like fences, vegetation and the likes, but more importantly any material properties like reflections, specularity, opacity, etc.
