My (older) K4 crams all the annotations into a single
Clippings.txt. I
assume the newer models work the same.

Kindles use a 'loc' to place the note.
My Kobo does something way different (both anchor and how stored).
I agree it would be wonderful if there was a universal converter so I could mark a (in my case) error, then open the Editor in Calibre and enter the Kindle 'loc' in the GoTo (Kindle Loc) ... and jump to where the correction was needed.
But sadly, all you do is get to store the note (model specific) at best.