I think to OPs point, we keep hearing that same line and I've never once seen a productionalized version of these
>>"never once seen a productionalized version of these"
YET
Just because we have not YET seen one does not mean it should not be pursued.
Examples are endless, start with: 30 years ago, no one had seen a solar panel with 25% efficiency produced for less than $1/watt. Now, it is the most economical and fastest-growing and most sustainable energy source on the planet.
That argument is simply an argument against all efforts at making progress. Perhaps rethink making it?
I'm not sure that's a big strike against it yet. Kinda the whole point of engineering in academia is to work on hard things that are far from commercialization.