Only when it's the literal only option at checkout. Then it's the merchant's choice, not my problem. When possible, I'll always opt to use a different instantaneous method (e.g. iDeal or direct debit), or give the merchant my money directly and wait 3 days for the IBAN transfer to go through. Using paypal just risks the money being indefinitely frozen on either side and them taking a cut for the privilege, if it works on a particular day in the first place (no mysterious errors or infinite loading screens)

As for "the real world", there's cash and chip+PIN. Never used paypal IRL. Is that a thing in your country, did you mean that literally? If so, where are you from?

If the merchant screws you on a transaction paid via IBAN transfer, how do you get your money back?