I would imagine American companies can easily outpay anyone on the global market of remote workers. No GC really just sounds like a problem for the non-american companies who are now competing for their local talent with tech giants.

Who do you owe taxes too out of your paycheck?

Wherever you are domiciled.

Incorrect if you are a US citizen. By default, on global income, a US citizen owes both US taxes and whatever taxes the country of residence charges. Thankfully many countries have tax treaties with the USA that avoid at least some of this double taxation.

By default, US citizens overseas have the first $108K of foreign earnings excluded, but they still need to file.

The US used to be unique in taxing citizens resident abroad, but Australia has in the past few years started to.