The point is that we allow competition from China but they can’t compete in China. It’s asymmetrical competition. The Chinese companies have a bigger population of customers (so more access to make money, more people to serve and grow from etc).
China protects their businesses from American competition but we don’t protect our businesses from Chinese competition.
Define well? There is no singular dimension of “well”.
Protect them from international threats works if the goal is stabilizing domestic business for national security purposes. Ask airlines for most of their history. Or look at the ability to use American car factories for the defense production act.
Will it produce the best product for their customers? Probably not. Look at American made cars. Not the best product.
Will it produce the best outcome for employees? American car companies employee thousands of union jobs that pay very well.
What if we successfully starve the competition? What if we don’t? No amount of government intervention was able to kill foreign car companies. But American car companies are still chugging along providing valuable employment to many Americans.
China protects their businesses from American competition but we don’t protect our businesses from Chinese competition.