So there's really accurate ways to detect "pure AI". The AI music detectors out there are mainly looking out for production things:

-a flatness to the EQ spectrum that you wouldn't get out a properly mixed and produced piece of audio

-no good stem separation, so no per-source eq (relates to above point)

-change BPM mid-song

-unnatural warbles at the end of every phrase

-vocals will have these weird croaky voice cracks, or sound scratchier and raspier

There definitely are tell-tale signs of "pure AI" in audio, but it becomes a lot more nuanced when any sort of secondary mixing/mastering/compression happens (which is the case 90% is the time in the real world- anything on YouTube/Spotify get's compressed).