The machines at the very top are the only ones at the very top, yes. But there are dozens of manufacturers and fabs building useful ICs slightly shy of the bleeding edge. Lots of microcontrollers, general-purpose ICs, and special purpose ICs are still very frequently made on 22nm and 45nm scales.

And most of the hard trial-and-error discovery and experimentation has been done already, so it should not take 50 years to recover 50 years of historical progress. A process from 1970 can be done in the garage with 'just' a microscope and projector (and a lot of skill and hard work!): http://sam.zeloof.xyz/second-ic/