I think it was clear that they were saying anybody is permitted to build a RISC-V chip, not that anybody has the skills.

> The number of people who can design a chip implementation

Thankfully you don't have to start from scratch. There are loads of open source RISC-V chip implementations you can start from.

> get or own a FAB to manufacture the chips

There is always FPGAs and also this:

https://fossi-foundation.org/blog/2020-06-30-skywater-pdk