User story: As a viewer of other people’s book ratings I want those ratings to have been made relative to some relatively objective standard so that I can better evaluate books I’m considering.

Expanded info:
When people are writing reviews it would be helpful if The StoryGraph provided meanings for ratings so they can be more consistent.

Here is the scale I use and find useful, and hope you find it useful, too:

5 stars: One of a small-ish list of best books I’ve ever read. When I finished, I said “Whoa," and either proceeded to read it again immediately, or pinned it for review again sometime.

4 stars: A good, well-written book that I’ll remember and speak positively about, but am unlikely to read again.

3 stars: Serviceable, but likely won’t remember it very long - or will speak of it as “Ok, but a disappointment”.

2 stars: So bad it makes me sad for the author, and other readers.

1 star: I can’t reach past chapter 3, even as penance for my sins.

Of course, users are not required to use this scale, and can use their own. But I'm willing to wager that most people's ratings are not intentionally / objectively defined, nor consistently-applied. Providing a rating guide does the work of the first job, and gently encourages the second.