At the end of the day, this is just a matter of keeping track of numbers. But there's no reason for merchants to have to remember the VAT rates for every country in Europe, let alone the world. We've all got computers, don't we?

What we need is a service that maintains an accurate database of tax rates around the world (not just Europe) and abstracts away all the calculations and remittances so that merchants don't need to care which countries they're selling to. Perhaps payment gateways like Stripe should offer such a service, either as a default feature or for a small additional fee. Perhaps the buyer's card issuer should do it instead.

Either way, I don't think there's anything fundamentally wrong about the new VAT legislation. Unless you're actively trying to evade taxes, the only thing the present controversy highlights is how little we've been thinking so far about accommodating diverse tax regimes in our payment systems.