People were wrong.

We pay money online mostly through credit cards. Credit card transactions can be reversed. If children spend money on porn, those payments are likely to be reversed. This is really bad for the ability of the porn sites to continue receiving credit card payments, and continue making money.

An age header is a trivial step that can reduce the odds of the adult site receiving payments that later get reversed. Win, win.

But if someone is willing and able to pay, then the adult industry wants the choice of whether to access content to be up to them. If government tries to regulate them, they'll engage in malicious compliance - do the minimum to not be sued, in a way that they can still reach customers.

For example Utah tried to institute age verification. The porn industry blocked all IP addresses from Utah. Business boomed for VPN companies in Utah. Everyone, including porn companies, knows that a lot of that is for porn. But if you show up with a Nevada IP address, the porn's position is, "You're in Nevada. Utah law doesn't apply." Even if the credit card has a Utah zip code.

If you live in Utah, and you're able to purchase a VPN, the porn companies want your money.

>But if someone is willing and able to pay

If someone is willing and able to pay, they have a source of money. If they aren't allowed to buy something, that control should be applied at the level where they get the money. If the child is using an adult's credit card, responsibility lies with the adult. If children need to have their own credit cards, the obvious point of control is the credit card itself.

But also, most porn is ad-supported, pirated or free. Directly paid content is a small fraction. So all of this is moot for porn.

There was a random comment here on HN few days back that adult contents have lower chargeback rates than everything else.

So ig stop spreading hallucinatory misinformations?