At the moment, combining your statement "I’m not sure that I could distinguish them from a nice ray-traced scene" and adding "your graphics card can move through them in real time so cheaply that it can easily be used as a component in other tech even at high frame rates" covers it pretty nicely. There's some research into how to make them move or do other things they don't do very well, but the fact that you can swoop through them in real time on cell-phone level of power means they fit a lot of niches. Plus the fact you can "record" them from a real-world physical environment without ever having to "model" it opens up a lot of utility too.

Personally I suspect they are getting a bit more attention then they "deserve"; people aren't talking about their weaknesses very much and I think that's resulting in some overexcitement. Some of the "we can replace everything with splats!" reminds me of the people who still don't understand why "if GPUs are thousands of times faster than CPUs why don't we run everything on GPUs?" is basically not even a sensible question. I don't see them as ever being the foundation of a graphics stack, but they definitely have a place as part of a well-rounded menu of techniques that can be brought to bear on a wide range of problems.