Good point. I should have clarified that I'm referring specifically to PayPal in the US, which themselves state that "PayPal is not a bank, does not take deposits and is not FDIC insured".
It isn’t subject to the EU statutory deposit insurance, however.
Edit: The above means that deposits on your PayPal account aren’t insured, different from regular bank accounts in the EU. This is a frequently emphasized caveat regarding the use of PayPal as a bank account in the EU.
You'd be surprised. A lot of sellers don't "cash out" from paypal all that often, letting tens of thousands pile up. (And inevitably, some of them get hit with arbitrary account closures and have that money seized)
https://www.paypal.com/us/legalhub/paypal/program-banks-tnc