[deckard1]

globalization, cheap easy access to air travel, and the internet are breaking down the systems that were working fine for countless years.

It's not limited to employment, either. Create a SaaS or other internet-based business and try to serve customers outside your nation. Or even outside the border of your state/territory/province. Entire services such as Paddle exist just to deal with this. But I suspect most people are trying to fly under the radar here using regular Stripe, etc. and not dealing with any of it, just like digital nomads do.