While there's only a limited number of competitors in the high performance ASIC fabrication suitable for fast desktop CPUs space, the number of companies that operate plants that fabricate semiconductors is a lot larger: https://en.wikipedia.org/wiki/List_of_semiconductor_fabricat...

It's also notable that a lot of companies who outsource new chip development still have substantial ties with the people building their foundries and maintain significant capabilities for manufacturing. IBM for instance, could probably run enough of its own fabs again to not rely on fabs from others if it really wanted to.

There's also a small handful of fabs owned by governments and universities.

And while the trend lately has been towards fabless companies, companies who do their own stunts and run fabs are pretty valuable because of it and eventually it seems likely an area some companies may want to play with again.

For instance, can anyone think of a company with billions in cash reserves, a huge bent towards owning as much of its own supply chain as possible and a need for a lot of chips?

I can.