They are payment provider and collect SEPA, Klarna, PayPal, Visa & Mastercard as well as Direct Debit / subscription payments on your behalf without the need of having any single other Merchant Account.
All in One Solution but with fees I have in mind 3-5%.
They are reliable and already for years around. They are popular for selling high ticket︀ digital products like video course, coachings and online academies 5-10k EUR price range isn't an︁ issue and you safe the headache with dealing directly with paypal.