https://www.paypal.com/uk/webapps/mpp/ua/upcoming-policies-full?locale.x=GB
In there you'll find terms like this:
In representations to your customers or in public communications, you shall not mischaracterise or disparage PayPal as a payment method.
If you enable your customers to pay you with PayPal, you shall treat PayPal’s payment mark at least at par with other payment methods offered.
Also excluded are payments to:
crowd-funding and/or crowd-lending platforms.
But you should just accept, they say, because Paypal is "faster" and "easier" than the alternatives.........
-This is where I could insert an animated gif of a ostrich with its head in the sand, but that's just not classy.-