Maybe you mean "how few"?
AFAIK, the only companies able to produce modern chips are Intel, TSMC, Samsung and GlobalFoundries; and Intel only makes chips for very select third parties, such as Altera, which they did ultimately buy.
AFAIK, the only companies able to produce modern chips are Intel, TSMC, Samsung and GlobalFoundries; and Intel only makes chips for very select third parties, such as Altera, which they did ultimately buy.
It's a bit like how separating railway infrastructure owner and railway operator is good for having more competition among the operators. If you need to build a whole network to run a few trains (compared to renting it on existing infrastructure), then that's a pretty big moat.