This is purely speculation on my end but paypal has too much friction from a consumer standpoint for me.

I pay mostly with credit card (debit really but entering the number etc). When paying with PayPal, I need to click through several screens to even be able to enter my details. They almost always show a login screen, then I have to find the small text at the bottom that says I dont want one. Then by default they want my SEPA details, which Im not going to give them, before allowing me to select Credit Card. Even then I still have to double check that the "Create PayPal Account" checkbox is unchecked before paying.

Stripe immediately shows you a form and doesn't ask any questions.