Seamless Paypal integration. Paypal is very popular across Europe (and the world), and many prefer to use it over credit and/or debit cards (these payment methods aren't universally popular).
Some people don't WANT PayPal. I had a bad experience with an eBay /PayPal charge back scam 5 years ago. I.e. freezing of my entire account and no human to find to unfreeze it.
I will never accept PayPal for the rest of my life.
yeah, braintree only has a potential benefit over stripe once you're forced to start caring about conversions & breakages (countries that expect to use PayPal, old people who trust the brand, etc)