The rest of the world does not necessarily have decent labor laws. What if you end up cheering on a terrible employment standard & reward anti-worker countries and economies?
Salary is a function of supply and demand. By expanding to Poland, the supply of labor increases, so overall SWE compensation goes down. Collective bargaining can only work by artificially constraining the supply of labor such as preventing a Polish SWE from having the ability to undercut an American SWE's salary, which disincentivizes hiring in Poland.
Sort-of. But programmers tend to create more work for programmers.
Letting people in less fortunate countries work for foreign multinationals would give them more alternatives.