Beta splatting seems pretty promising. It addresses the fuzziness aspect of gaussians among other things.

https://rongliu-leo.github.io/universal-beta-splatting/

https://linus-franke.com/hibs/

There are various papers on variants of Gaussian splatting (keyword "differential rendering") which replace the Gaussians with some other explicit geometric representation that can also be rendered in real time. A triangle soup is just one example. I recall one which uses some sort of tetrahedral foam instead.