I don't disagree, but my example is extreme and ridiculous simply to make the point that there is a line at which an agreement cannot be held to, even if it is agreed to. We can't decide where that line is here, I just wanted to establish that there is one and the claim "It was in the service agreement" is not the final word in a legal sense. What often seems obvious in the law can be subjected to all kinds of legal challenges and can go either way depending on what court it goes before. A lawyer might ask: Did the person fully understand the agreement as stated in the agreement? Does it use legal terms a layperson is not expected to fully understand? Is there some other privacy protection that these terms conflict with? And so on.
Ehh civil law is pretty settled here, at least in the USA. Courts have ruled that as long as the consumer has had the opportunity to review the details of the contract / agreement, that both sides are receiving some sort of compensation and the agreement doesn't violate existing law, then it's a legal and enforceable agreement.
The first stipulation is why everyone product presents this giant multi-page "Terms of Service" to you, and that you must click "Agree" to continue with. The second is why you must click "Agree" to use the product and clicking "Disagree" shuts the product down. Essentially the owner of the production is allowing you to use the product in exchange for you agreeing to their terms, which includes them owning the usage data from that product. That third is where States can get involved, by making it illegal for companies to use your data outside of certain boundaries.