I think this highly depends on what is being rated. Non-durable consumer goods, sure, there is very little assurance that what you're getting now is even what y

I think this highly depends on what is being rated. Non-durable consumer goods, sure, there is very little assurance that what you're getting now is even what you would have gotten ten years ago. Processes and inputs both change. A previously reputable brand might have been purchased by private equity and enshittified on purpose. On the other hand, if you're reading reviews of Moby Dick, I don't think the perceived quality or relevance of the writing is going to change much on the scale of decades. Maybe it starts to get archaic at some point, but people still get a lot out of reading Homer. If it's something like Principia Mathematica, that might honestly be timeless as long as human-like creatures exist who can read and understand math and physics.