Your description of that trope in the Old Guard and elsewhere makes a lot of sense to me. It reminds me of when I first started playing at Milliways and how there were some characters that seemed to build their characterization around I'm more broken than you. I wouldn't have thought of it with that scene in the The Old Guard but its kind of there.

The Murderbot books are on my to read list, I've liked Martha Wells before but I'll see.

Myths and Fables also really disappointed me, none of it was badly written but they didn't seem to actually go into actual world building or proper myths. One of those books I was glad that I borrowed from the library.