I feel like the writers have so little wiggle room to do characterization when the characters are committed to a long narrative arc. No rando stand-alone, self-contained stories that edify and deepen.

Yeah, I get that. TNG had a lot more room to play with Data's quest for humanity than Picard. Which is ironic, given that Data was about as important as Picard in the second series.

But I also didn't need to watch Beverly Crusher have sex with a ghost. So, trade-offs.

It is the second most depressing aspect of NuTrek with the first being that Trek stopped being about presenting a utopia vision for the future.

I always found the Utopianism of Old Trek overstated. More often than not, it was the Trek crew stumbling on some alien race or society that was experimenting with another Sci-Fi author's idea of Utopianism. And then the Trek crew became the vehicle of Rodenberry's critique of the utopian philosophy.

I do think a lot of the NuTrek writers keyed in on the season long conflicts in DS9 and decided "This is what we need to do going forward". And, as a result, you got these increasingly narrow, black-and-white, action-focused adventures (the post-OS movies were the worst offenders of this trope). The apex of this (for me) was JJ Abrams blowing up Vulcan in his movie adaptation, so he could do Star Wars in Starfleet Uniforms.

But if you go back to the older episodes, I might argue that it was the captains who were Utopian. But the Trek Society was still very militant and authoritarian.

I would actually argue that Seth MacFarlane's Orville did a much better job of painting a utopian intergalactic federation than Rodenberry or his successors ever did. The culmination of the third season really painted the triumph of politics and inter-uh-galacticism over Realpolitik and imperialism.