It actually already exists in some countries so USA would not be first unionising software workers. That would seriously help with the outsourcing problem if everyone would get the same benefits in all countries. Stop outsourcing everything to China would probably stop them from growing into the superpower it has become during the last decades. But I guess that train has left the station already.

Doesn't even have to be a global single rate, just a way to collectivize the negotiations worldwide while still accounting for local economic conditions.

Business people form conglomerates together whenever it makes strategic sense. How this became so stigmatized an action for business people selling their own labor makes no sense at all.