"explorable" and "immersive" is definitely a bold choice of words when you can't really get below the level of the buildings before the gaussian splatting is very obvious. Sure, it's impressive that you can get that detailed from a few satellite images, but I think that might be overselling it a bit
We're early days. Models will soon interpolate all of that. Eventually in real time.
I wouldn't knock the research. The results look impressive to me.
That's a matter of data, and this looks promising to me. If instead of satellite images they'd feed it drone shots they could probably get down to a level of detail that becomes actually immersive and would be way beyond the digital twins we currently have.