I think I had really unrealistic expectations based on the "Best episode of Modern Trek" reviews and comparisons to Measure of a Man. It was a good episode, but maybe I need to rewatch the season 1 episode referenced here, because I don't really get the persecution of the Illyrians. It just didn't feel like they did any work to make that feel real, other than the brief flashback sequence.
So when Una gives her testimony of her persecution, it feels hollow because it's obviously allegory (and with the idea of 'passing', likely a Trans allegory)... but given how we live in a world where Elon Musk wants to have 50 kids because he thinks his DNA is more valuable than anyone else's DNA, my brain can't accept the notion that people who practice eugenics are repressed class. That was handled better on DS9, and I know that here it's allegory and not the actual issue being discussed, but it made the ending feel a little hollow for me.
With Measure of a Man and Drumhead, it was very clear why the system was working against the person on trial. Even the Voyager episode with the Doctor and his holonovel. Here it just didn't have the same effect on me because it needed more development.
That, or I really do need to rewatch that S1 episode.