To make matters worse, Paypal has extreme platform lock-in. For example, you can't move your users billing to another platform; you have to get the user to sign up all over again. On top of that, you have to hope they have another form of compatible payment (i.e. mobile payments, credit card direct, etc).

Paypal holds all the data and when they ban you for whatever reason, they keep it, so even if there is another option, once you commit to Paypal, you are committed.