....or, you just use the same timestamp mechanism available for code signing. Aka you ask a CA to issue a signed timestamp against a content hash and while you are at it, you can get multiple CAs in it.
The fact that there are other ways to work around previous limitations to accomplish something doesn't render the use-case invalid. The GP was asking for a usecase outside of currency and one was provided. If a valid use-case for electricity was asked, and someone described a lightbulb, you could just as well say "...or, you could just use an oil lamp"