Funding Released for Sabre Rocket Hypersonic Project
 

From the good ol' UK taxpayer no less.

We may all be in the gutter, but some of us are looking at the stars....

Funding flows for UK?s ?revolutionary? Sabre rocket engine - BBC News

Getting this engine concept to a viable product will require $billions, and not just the few $millions of funding it has been given. While the basic concept is interesting, and the results of bench testing done on subsystems like the heat exchanger seem encouraging, there is still a massive amount of work required to get it ready for flight testing. Unfortunately, I don't think there is enough commercial demand for this engine concept to justify the massive development cost involved.

Yes, "they" told Henry Ford, Whittle, Von Braun, the British space industry (1960s) and no doubt Ellon Musk that too.

And they also said that to the developers of the pneumatic railway, the Rotordyne and the hovercraft. For pneumatic railway, read now Hyperloop.

Mr Parrot, I'm not sure what your examples are intended to illustrate, but remember the Rotordyne flew beautifully and was killed by noise, not technology and the hovercraft has been and continues to be a considerable success.