In europe, Paypal Sarl is a bank subject to bank regulations

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".

https://www.paypal.com/us/legalhub/paypal/program-banks-tnc

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.

Is that an issue if you don't plan to "store" money in PayPal but only use it for payments?

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)

In that case it isn’t, but this thread is specifically about holding money in PayPal: https://news.ycombinator.com/item?id=45250598

My point is that one doesn’t get all the protections normally taken for granted for EU bank accounts.

The question is if a EU bank has to provide deposit insurance but PayPal does not how can PayPal be a bank.

PayPal might be a bank but maybe PayPal accounts aren't bank accounts

I haven’t researched the details, but it doesn’t work that way, because they aren’t providing regular bank accounts.

But they don’t offer deposit guarantee. Banks usually have to in the EU