Even Reddit agrees but the developer didn’t have a choice. He responded to someone asking why PayPal:

I've had my business accounts closed down by 3 major high street banks and rejected by almost every "app bank" like Wise, Revolut etc.

We've basically been forced into using PayPal to facilitate transactions as it was the last way we were able to send money to each other/pay contractors. The business account I am forced to use is with CardOneMoney. They charge me £15 a month just for having an account, 0% interest, and they charge me massive fees for every single invoice I have to pay.