>In most parts of Europe, PayPal is pretty much unheard of
Thats depends a lot on the country though. Not accepting PayPal in Germany would probably be the same as not accepting credit card in the US. In the UK however only offering credit cards might work.
In Scandinavia, the only people who know what PayPal is are the ones who maybe bought something over eBay, or the ones wanting to send money to a friend in the US, and being completely surprised by how hard that turns out to be.
There's 0 domestic use cases for PayPal there. Other parts of Europe I'm not so sure about.
Thats depends a lot on the country though. Not accepting PayPal in Germany would probably be the same as not accepting credit card in the US. In the UK however only offering credit cards might work.