It's important to disentangle this specific approach of generating a gaussian splatting model from 2d images, with gaussian splats as a general rendering technique.
There is nothing that prevents gaussian splatting from being used dynamically. There are a variety of approaches to extend gaussian splats into the time dimension to capture and represent a 3d scene over time. The challenges here about how to capture sufficient scene data (or use ai to fill in insufficient data) and how to compress it. There are also techniques that enable dynamic simulations, or real time animation of collections of splats.
Also, adding un-baked lighting to gaussian splats is not particularly hard, you can already throw slats into several game engines / 3d renderers and add new lights to them. The hard part of relighting is taking an existing capture of a scene with baked-in lighting and deriving the resulting material properties and lighting sources. This isn't directly related to gaussian splats themselves though, you would have a similar problem recovering the base materials and lights from a 3d mesh with baked-in lighting textures. This really falls under a separate category of techniques called "inverse rendering". If anything, gaussian splats give us a new tool to help with these sorts of problems.
Honestly the biggest remaining roadblocks to more elaborate and widespread uses of gaussians as a rendering method are probably storage and performance related. And I'm optimistic these will be convincingly solved, triangle rasterization has had many orders of magnitude more research, optimization, and custom hardware built around it.
There is nothing that prevents gaussian splatting from being used dynamically. There are a variety of approaches to extend gaussian splats into the time dimension to capture and represent a 3d scene over time. The challenges here about how to capture sufficient scene data (or use ai to fill in insufficient data) and how to compress it. There are also techniques that enable dynamic simulations, or real time animation of collections of splats.
Also, adding un-baked lighting to gaussian splats is not particularly hard, you can already throw slats into several game engines / 3d renderers and add new lights to them. The hard part of relighting is taking an existing capture of a scene with baked-in lighting and deriving the resulting material properties and lighting sources. This isn't directly related to gaussian splats themselves though, you would have a similar problem recovering the base materials and lights from a 3d mesh with baked-in lighting textures. This really falls under a separate category of techniques called "inverse rendering". If anything, gaussian splats give us a new tool to help with these sorts of problems.
Honestly the biggest remaining roadblocks to more elaborate and widespread uses of gaussians as a rendering method are probably storage and performance related. And I'm optimistic these will be convincingly solved, triangle rasterization has had many orders of magnitude more research, optimization, and custom hardware built around it.