It's inherently unfair because its used to drive down wages of the lower classes. Outside of highly skilled work that cannot be sourced from within the country that is critical for nation security, the moral response is to just pay the workers more.
While I don't disagree, and while I firmly believe in UBI (which is the natural conclusion to your logic), without a comprehensive plan in place, just "paying people more" will be a bit of a death spiral since that is a core contributor to inflation on a large scale.
Because it’s economically insignificant. Total CEO pay across the Russell 1000 excluding Musk is in the tens of billions. Paying a few people more isn’t inflationary. (It’s other kinds of problematic.)
There seem to be social consequenes to that sort of income inequality. There are solid arguments for enabling founders to become fabulously wealthy. The argument seems a bit more stretched for managers.