> Every company selling goods and services to European customers needs to collect value-added tax (VAT), even if their business is not established in Europe.
> Enforcement of judgments issued by foreign courts in the United States is governed by the laws of the states. Enforcement cannot be accomplished by means of letters rogatory in the United States. Under U.S. law, an individual seeking to enforce a foreign judgment, decree or order in this country must file suit before a competent court. The court will determine whether to recognize and enforce the foreign judgment.
Obviously, its not a good idea to bet your business on the courts not enforcing an EU fine when you can just add the VAT and cost of the handling hassle to the price for EU customers.
The operating idea from governments is that in the digital age, when you sell something to a customer abroad, you're selling to them on their turf and not yours. That's why you're considered liable for sales tax in the first place. Doesn't matter that your own country of residence may or may not care. For all intents and purposes it's as if you physically flew to the country and hand-delivered your software/product to your customer.
It's clearly an awful "patch" to outdated concepts on how commerce works compared to pre-internet, but it's what we have right now.
https://stripe.com/guides/introduction-to-eu-vat-and-vat-oss