American companies are prudes, as the country tends to lean that way, nothing new really. Seems people never learn though, which is more worrisome.

The companies are prudes because the countries they operate in, as well as the payment providers they use, have laws and regulations regarding age-rated content.

Having terms & conditions and blocking users that violate them is easier than dealing with the legal problems that may cause them.

Restricting access entirely is another way, like what US based websites do for EU based visitors, or what Pornhub does for Florida.

I think the prudence is why the US have those laws, regulations and morals, not the other way around which you seem to point towards.

Many years ago, I used to work for a company specialising in IoT devices. One of their projects was about teledildonics and required the purchase of some ... testing gear. At the time they had their book keeping on Google Drive and when the invoice for said purchases had passed through their emails, their entire workspace was suspended for a couple of days until they could clear it up.