Let's be realistic, here. That wouldn't happen. It's politically difficult enough to keep the US Postal Service solvent, and they're essential for providing mail service to lots of places for-profit shippers won't touch.
Not only would you need to scratch up the funding to bootstrap such a venture, but there's the whole technological deficit you'd have to overcome, in order to develop a remotely modern node. Relying on a national fab would basically be the quickest way to set us back about 15 years or more, technologically.
If you remember how hard it was to get chips from 2021 - 2022, that same sort of supply shortage would occur on an even larger scale. That would be very disruptive to the world economy. The funding programs in both the US and Europe are both aimed at building up some reserve capacity, in case of just such an event.
If they have fabs on US and European soil, and if we can somehow encourage them to make those fabs sufficiently independent of the mothership, then they can be part of the solution. Even now, it's not as if Taiwan is the ideal place to manufacture chips - last year, they faced historic droughts that threatened to limit production, since chip manufacturing uses lots of water.
That's how private/public partnerships work. We chip in a little public money to top up an industry on the brink, and suddenly it becomes profitable enough to stem the tide of manufacturers shifting operations overseas.
It's a lot more expensive to build up a new industry than to save an existing one. That's why it's important that we stem the bleeding and reverse the losses in semiconductor manufacturing.
I've said before that this isn't going to be a "one and done" scenario. CHIPS is a down payment that will need to be followed with some additional funding, as we near the end of its window. We provide agricultural subsidies, because we all understand how important it is to protect our food supply. Semiconductors are becoming almost as vital for our other industries and overall economy.
Nothing about this statement is true. Even ignoring how vital cloud computing and smartphones are to modern society, tons of industrial equipment has advanced semiconductors in it. As does a vast array of products, from bluetooth headphones to security cameras. Not only that, but we also saw how hard the chip shortage hit the automotive industry. And so many of us that attend school or work partially or fully remote cannot do so via fridge-level technology. Forget about online gaming or video streaming.