Maybe if I want to send my friend $5 Paypal or whatever can do that, but what fintech is actually taking market share from them at merchants?

Maybe it is because I am in Germany, but merchants here only accept cash, girocard and credit cards - online shops obviously have a wider selection that regularly includes Paypal in Klarna, but I wouldn't expect credit cards to loose a lot of market share to them.

So in which geographic regions is this actually the case? Do you have any source I could read on this as I am quite interested.