Actually sorry not sure if they use triangle splatting, but gaussian splats at least.
Media Molecule (LittleBigPlanet) spent over 8 years creating Dreams, which would never have happened without Sony's funding, but the tragedy was forcing what could have been a brilliant high-end authoring tool into a gamepad / lean-back interface. Even now, there are still innovative UX approaches in Dreams that could be adapted into high-end 2D, 3D, compositing and animation tools like Blender.
At one point it used triangles for the large splats, and still compute shaders for the small ones due to quad overdraw. I'm not sure if the final version stuck with that or went all compute, but quad complexity is also why nanite does compute shaders for small triangles and traditional rasterization for the larger ones.
Things like triangle splatting are useful if you have to integrate into an engine that only support triangles. But with modern graphics pipelines, you can implement Gaussians quite efficiently, including newer techniques like Gaussian point splatting that can scale up seamlessly to enormous scenes:
* Video: https://www.youtube.com/watch?v=2AWv_nIfp-U
* Paper: https://jorisar.nl/gaussian_point_splatting/gaussian_point_s...
runs on a phone: https://storage.googleapis.com/jax3d-public/projects/mobilen...
To be clear, I'm not proficient in it's use, just watched a few videos about it's theory when it was initially announced