the proof is your purchase; if you sign up for a service and the terms of use are "by using this service you agree", and you use the service, you have legally agreed. even if you SAY you disagree, you are still using the service. you legally are bound by the ToS. please learn the law.
it's true that people don't read TOS/EULA, but that's not the fault of the company. it's true that many companies write obscenely long ones to deter the impatient consumer from reading them, but ignorance of law is not an excuse; if you break contract, you are at fault, even if you didn't know it. this is how the law works.
You know most of the EULAs aren't legally binding, and in most cases not only can't be enforced but are illegal in the terms. Live services they can refuse you service certainly, but i'm not talking live services.
Though i'm sure you're the type to agree with Disney that if you try a free 1 month trial of Disney+ then you have to relegate all legal matters to the end of time through arbitration through Disney and not sue them...
the proof is your purchase;
Then i will never purchase. Problem solved!