Actually it's not true even as far as the law goes - from a straight unauthorized charges/fraud/lost card/etc perspective, the controls are very similar between credit and debit cards. There are a few differences around notification times, but fundamentally you're not liable for fraudulent charges. https://www.consumer.ftc.gov/article...c-banking#lost

However what debit cards generally don't have are the protections beyond that point. 'Often1' specifically mentioned an airline going insolvent, not a card being stolen - and I'm sure that was deliberate as for something like that the protections are completely different. With a credit card, you're covered (based on the merchant not providing the services), and your credit card company will provide a full refund. With a debit card, you're generally not covered.