Useless for people living in more than one country
You can't add a foreign bank account without changing your address to the appropriate country, and the site won't allow you to change your address to any other country at all. The only way is to open a second Paypal account. And by then, Paypal will block the card you've tried to assign the first account - rendering it useless altogether.
Then, as a scam, if you try to use your original domestic bank account for a foreign purchase via Paypal, they insist on converting funds between currencies themselves, at exorbitant rates, without giving you the option to choose your own institutions provided rate.