I think in the initial stages you had to have a PayPal account, maybe it’s expanded to bank account details lately?
You mean on Depop? They used to have their own in-house “wallet” which was great because they had full control of the transactions, but they since switched to Paypal and personally I found it a nightmare, even purely on the technical side of things, but the main issue is that they now rely on Paypal’s awesome () customer service as their main method of “buyer protection”, which IMO is a big downgrade from the early days of Depop Wallet.
In any case, Depop are cracking down on out-of-app payments, partly due to the huge amount of scams where bad guys put up products that don’t even exist, ask for a bank transfer payment (to avoid the 10% fee) and then disappear. You would think that a fraudulent bank transfer should be easy to reverse (in fact, I personally trust an UK bank more than a Paypal account, since the latter is tied to an identity, while a Paypal can be opened by anyone under a fake name), but clearly neither UK police nor Action Fraud cares about those scams.