I'm not a lawyer but based on some googling it seems like the overwhelming consensus is that selling transcribed sheet music or tabs if you do not have permission from the copyright holder of the song is illegal.

https://www.thatgreatcomposer.com/blog/is-it-legal-to-transc...

https://law.stackexchange.com/questions/96352/dual-question-...

https://www.drumforum.org/threads/what-is-the-legal-basis-fo...

As an occasional amateur music transcriber I'd say the goal of transcription is not transformation. If I'm transforming, I've failed :)

Inevitably the transcriber makes decisions in how to deviate from the reference recording, be it omission of instruments, microchanges in tempo and pitch or articulation. In theory a good transcription is an exact graphical representation of the abstract sonic intent of the artist.

Of course, if you are combining voices, changing chords, it approaches an arrangement which is a more creative endeavor.

> Transcribing is transformative.

Not under US Copyright Law, it isn’t. Transcribing is derivative, not transformative.

BTW, if it was transformative, it’d be fair use and legal, and you’d be contradicting yourself.