We aren't talking about making new lug-nuts. A company can't just will a fab into existence.

For example, Micron is actively building a few new fabs. One of which has been in progress since Biden (pretty close to my home in fact). It's not going to be completed for another 5 years at a minimum. And this is a company that has the experience and partnerships for producing fabs.

Yes, a new company might decide they want to enter the market, but even if they decided, today, "Yes we'll do this" I'd expect a minimum of a decade before they start spinning out their first chips. That's also at least a $1T investment at this point to get started.