> Countries who want to make money via a territorial nexus usually use VAT or GST
Exactly, they have run into fundamental problems with income tax which is simply a bad tax scheme. From being counterproductive to easy to game (at a certain scale).
GSTs and VATs do "leak" for customers who personally import goods or services. So for example, Amazon collects no GST for the Australian Tax Office when I import books from them.
On the other hand, I receive no ability to offset my own GST collections against GST expenditures.
Every tax has problems. That's why every major economy has a bunch of different taxes that collect money in different ways for different kinds of economic events -- purchases, income, sale of capital/equity and so on.
Exactly, they have run into fundamental problems with income tax which is simply a bad tax scheme. From being counterproductive to easy to game (at a certain scale).