I think it is important to distinguish between the Vedic teaching and the Sutta teaching; otherwise one becomes a follower of the Vedic teachings; which includes the vibhava of dismissing these concepts as “mythology”.
If we read SN 29 to SN 32 carefully, we will find they are about kamma:
- The Naga engage in mixed kamma, serve the Supaṇṇa, but also can aspire to good kamma & to the other world/heaven.
- The Supaṇṇa are the most powerful; engaged in mixed kamma; not seeking the other world. The Supaṇṇa seem content with their worldly power in their world.
- The Gandhabba engage in good kamma.
- The Cloud Gods engage in good kamma.
The above was analyzed in detail at this post: Confused about SN29 (Chapter on Dragons) - #5 by CurlyCarl
Therefore, in general, it seems the Gandhabba is some type creative power (deva) for the good; seeking to preserve/advance life rather than destroy/harm life.