The rules for online businesses usually do not need you to operate physically in a state. For example, CCPA in California, is enforceable if you buy/sell/share personal information of California residents and generate revenue from it, even if your business is not in California physically. You can be sued and the state will pursue fines if you are in violation of the law.
Similarly, even if Pornhub doesn't operate physically in Texas, if they make money off of users residing in Texas, you are "conducting business" in Texas and therefore the laws are applicable to you as any other business.
The concept is known as "minimum contacts".