Overall welfare is about more than just income though. It’s about national security, the cost of living, and the benefits of things like innovation, technology, culture.
Let’s look at US imports from China. Last year that was $462bn worth of goods. Suppose the development of China never happened and all those goods were manufactured in the USA instead. That’s impossible, the US doesn’t have tens of millions of industrial workers lying around spare to do those mostly low end, low value jobs and if it did they would cost more and the goods would all be much more expensive. So the cost of living would go up, the economy would less efficient because many workers would be doing lower value add jobs than they are now. The country would be much worse off overall. It would basically amount to enormous government subsidies and protections for vast swathes of lower value assembly work than what many people are doing now.
I support global trade because I think it’s best for the west. Not hyper-liberal ultra free market trade. Negotiated, rules based, moderately regulated trade and investment that is balanced to meet domestic and international needs.