I find Pegasus a decent episode. I think that while utopian aspiration is a fundamental tenet of Star Trek, I think it’s a bit reducto e to call it completely a show about perfect humans.
Heck, from the get go we had Garry Mitchell doing pyscho god stuff and Charlie X groping people, and a captain who sacrificed his crew to the weird space Romans so he would survive.
I think in truth, Star Trek is both about the best humanity can be and how the best in humanity can overcome the worst in humanity - you can’t exactly do that without episodes where the protagonists or the Federation makes mistakes, sometimes small and sometimes on the magnitude of Pegasus.
In many ways, DS9, darker as it is, feels the most Trek - a team of very different people with different beliefs overcoming/respecting their differences and forming a beautiful community despite the folly and evil around and within them.
While DS9 quality is an issue, I think Keevan is just a PS1 character- a beautiful one.