This is basically the same as the UK proposal which the Register article is talking about - that's also credit card or valid ID, they just chose to focus on the credit card part in the article.

When I said credit card I thought it was obvious I meant that debit cards are also acceptable. Turns out it wasn't!

Even if you include debit cards, you're still wrong.

You don't need anything. At all. According to Google, in case they suspect you might be lying about your age, they _might_ require age verification. This can be done with a credit card or an ID card.

So no, you don't need a credit card to watch age-restricted videos. You don't need a debit card either. You probably don't even need an ID card or anything at all.

You don't need to be of legal age to get a debit card, but you do for a credit card, hence why credit cards are often used as age verification.