I'm not the original commenter you replied to, but I have thoughts that might be relevant. These things are quite subjective so some people will disagree that this is a good example, or with what I'm about to say so have a punch of salt at the ready…

I think "pretty average" is the thing to strive for in a README. The right balance of detailed but concise, not overly festooned with unnecessary verbiage like a stereotypical recipe page, a simple "what is it", "key features", "how to get/install", "more detail on features / example use" structure.

Of course it gets harder to find that balance as the size and scope of a project expands, you have to become judicious with cutting things out and excising them to extended documentation instead of everything being in the README. For a thing this size everything is close to the right balance if you word+arrange it right, for larger projects the README should be a summary of what, how to get, and where the other documentation is.

If this one is AI written (there are signs, but those are things humans have long done which is why AIs copy them) it has been human edited rather than just thrown up as-is.

> as someone who struggles to write readmes

If you are struggling a lot with that, perhaps you are overthinking it or trying to shoehorn in too much detail?