Another aspect is that selling to all of Europe as a B2C business is hard. Until recently you ended up having to register for VAT all over the place, god only knows how many different specificities, bureaus, and rules, with most payment solutions not helping you in any way, and most accountants (in my experience) being at best unable to help you in any significant fashion, at worst being very confident in their ability to help you.

It is done, but by very few. And the EU has made progress on uniformizing and simplifying it, but it seems to have done more progress on the B2B side than on B2C.

While the US is a much bigger consumer market than any single EU country, with significant differences in disposable income and spending power. 18% to 20% of full-time workers in the US make over $100.000. That's nearly half the entire population of France. A third that of Germany.

And even if there are differences and administrative hurdles when selling across US states borders, that road has mostly (or seems to have, from here) been paved.