This made me appriciate the amount of visa-free travel my passport allows me on a whole new level. Figuiring these things out seems possible, but so inefficient and time consuming.

It’s not just that. I’m about 1/3 in one country, 1/3 in another one, and 1/3 in others, with income from multiple countries… I pay all my taxes (even more than I should), but hell, I won’t make the paper trail completely clean, because there is pain there. A lot. Tax authorities are utterly incompatible with each other.