It's a global economy. There was a year or two recently where it was possbile to get every part made in America; but I think that is no longer true. Even if they did, it would make no sense to buy an American rear der, for example, for 4 or 5 times what the top Shimano costs.
For most it would mean buying a cheaper frame. Which usually means a non-American frame.
The reality is that we have economic interdependence. A lot of old guys want to hang onto the old ways. So their countries wind up subsidising various industries, Which usually kills them in the long run. It makes sense to protect a few key industries relating to defense. Beyond that, you are pretty much shooting yourself in the foot. You can point to losses created by this change. But there have also been gains. Americans by any historical standard are wealthy. We live longer, have more free time, more disposable income than quite a few kings in history. Capitalism is often called "creative destruction" for those reasons. . Sorry, but the basics are the same for us as they were when England was on top a century ago. And the basics include having a world class education system (our secondary education is a mess)..a healthy economy (our debt levels are a nightmare) and good relations with your neighbors (oops). Chasing after spilt milk is not a winning strategy.