Is it worthwhile for an ordinary Shanghainese to immigrate to the United States?

That depends on the purpose of your immigration.

If you have a job and a career in America, and your wife and children are there, it is still necessary and worthwhile.

If nothing happens, a person immigrates to the United States, leaves his family and friends, leaves his familiar hometown, goes to a foreign land to do nothing, and dies alone ... that's not worth it!