The better analogy here is that if a German band plays a concert in the UK, they still need to pay UK taxes on their ticket sales. Even if the band is incorporated in Germany, the portion of the tour that occurred in the UK is still subject to UK taxes.

Additionally, most European countries permit duty-free sales to foreign citizens in normal stores under the right conditions (often via requiring a passport to be shown at purchase, and via refunding the taxes at airport when leaving the country). This arrangement works because, it's generally required that travelers pay customs on arrival to their home countries on goods purchased abroad anyway. That being said, I've just learnt that the UK has killed their duty-free sales system as of 2021 [1], which is just stupid.

[1] https://www.executivetraveller.com/news/uk-to-axe-duty-free-...