[happytoexplain]

I disagree. The "tone" of the vast majority of AI to me has a clear identity, and is not related to poor composition. It is in fact "high quality", technically speaking, and is a separate problem from that of bad/strange genAI writing. In fact, some real people do write in a similar tone, which makes it hard to tell apart sometimes, which is the problem you describe, but that doesn't obscure the fact that it is the "AI tone".

[pxc]

It takes too long to get anything said and it has a very weak sense of topicality that it papers over with repetitious use of literal words and phrases from the things it's asked.

Afaict, it's 'high quality' only in the sense of not containing many grammatical mistakes or spelling errors, which of course is not 'high quality' so much as 'basic literacy'.

I think I know what you mean about other elements of the tone (staid and obsequious) not necessarily being related to style but they don't quite form a clear identity for me. The defects of the writing are still more marked than its personality.