> What's the difference for me as an employer if someone is remote from 10km away or 5000km away?

There is not - hence there are about 1.5 million software developers in the United States and approximately 1 million just in India alone. Probably another million in other countries across the world (I have 26 on my team working from the Balkans for US company).

already at present there are more devs working offshore than onshore and that trend will continue to grow