Here's an addendum with a few great episode examples which might pass my "test".
- TOS: "Amok Time", (arguably) "The Galileo Seven"
- TNG: "Brothers", "Lower Decks", "The Measure of a Man"
- DS9: "It's Only A Paper Moon", "Improbable Cause"+"The Die Is Cast", "The Magnificent Ferengi"
Other shows also have great episodes that pass, but I want to stop here for my examples so as to avoid showing my hand (too much) and stating which show(s) I think fail.
I agree with and second many of your statements in here. Well said! A couple specific points I want to highlight:
I really enjoyed those plots, especially about loss.
I think this is the core of the issue for what I enjoy and don't enjoy with many Star Trek shows. Surprisingly to me, Expanse does this fine whereas Trek/Who/SG-1 would trip over it and have.
In general, great reply with excellent points. Thank you!