This isn't strictly true, at least in NL. Most domestic online businesses use iDeal for instant payments, but if you aren't shopping at an online retailer that explicitly supports it, you need to use a real credit card or Paypal as a pass-thru. Some businesses will support you sending a payment via IBAN, but then you're waiting days potentially for someone to reconcile the ledger manually and deliver your digital product.

Since I don't particularly enjoy having debt, Paypal is a nice middle ground as long as the fees aren't outrageous.