Yeah, as someone interested in this kind of thing, I've been hoping someone else would put something together that would work, but I think I share your assumption that this is probably not something that can be made into a product profitable enough to finance a company on.

I will say that, for the most part, these companies try a kind of "lock you in to our product which uses open source" scheme that could never possibly work. And, further, that no one has ever implemented the kind of system that I have in mind that I've seen. But that's not because it's unique or complex, just that it isn't a good path to a minimum viable product, so it isn't a good way to spin up a company quickly.

But yeah; aside from burning through cash in order to build enough coverage (maybe a year of dev just on this; no product dev yet) for a product that you will never actually profit from, I don't see how anyone could bring something like this to market.

All of that aside, a product that can sustain a company is not the only way to have a product exist. Modular productization and loss leading are a couple of ways to envision this. But I'm betting some kind of fractional componentization starts happening that makes this kind of stuff more maintainable. YMMV, though!