Alright, so to begin with, not arguing for quality of one beloved franchise over the other as I find both series to be spectacular with various highs and lows as is to be expected for decades long franchises spread across multiple mediums and iterations. Thus, if you are looking for a writing that will tear down one over the other in terms of quality or superiority, this is not the post for you. The specific issue I wish to discuss is the approach of both franchises have taken in their attempts to grow and become more adult in theme and story.
As both series have grown and progressed there have been attempts, successful and not, to make them more mature in narrative and themes than their earlier incarnations. With Star Wars, it is a bit easier to do. After all, regardless of its classification as science fantasy or fiction, the story of Star Wars was always a childhood fantasy. The last member of a monastic, space wizard order, who also happens to be the child of a child of prophecy, saves the day from the literal evil version opposite of his order by being kind and hopeful to a father he never knew is basically a fairy tale meant to impart moral lessons to literal children. And the main films have mostly followed that logic of clear heroes and villains. Even the few attempts to have more gray morality in some of their characters in the films were executed poorly or nonsensically to end up with more exasperation than intelligent consideration.
However, there was more success in television. Andor, Mandalorian, Bad Batch, and various of the cartoons as those were able to legitimately complicate the morality and philosophy of the universe beyond the simplistic good vs evil or Jedi vs Sith. One of the major reasons these worked was because the initial story was so simple that it demanded complication to expand and give depth to the universe at large. It was always a little ridiculous that a single man winning a single fight would change the make up of the entire universe. Thus, we see what it actually took to build a rebellion and what the conditions were that would cause the populace to rebel in the first place. And because war is hell and messy, we also see the nuances of actions and choices taken by characters like Saw, Lucien, Cassian, the surviving clones, etc. to ensure survival, victory, and just having a basic fighting force to act against the Empire. Of course, we also see the ignorance and avoidance of action that the New Republic take to ensure the continuation and eventual rise of the defeated empire. It is dark and mature and complicate because it set itself up to be out of necessity from such a simple story. But it works because of those origins and care in ensuring growth without tarnishing the origins.
On the other hand, Star Trek has not had the same ease. While it has also had equal success in film, television, comic, and cartoon across the decades, the series has mostly stuck to its central thesis of a utopian future that has moved humanity pass its difficulties and into a new age of unity, peace, and exploration. And that from that new evolutionary phase, a Federation of like minded planets and species have united to present a combined force to meet hunger, war, pain, pestilence, and other hardships with care and aid. This may seem like a childish fantasy as well, but the difference is that Star Trek has always presented itself as a far off aspiration that humanity achieved. Obviously, outside of a few technological advances particularly in space exploration, the path to get there has been left ambiguous and open ended because it is still unclear, but the basic conceit has always been that humanity managed to achieve that goal. And unlike, Star Wars, Star Trek has matured its universe by basically showing its utopia to be a farce and achieved and maintained how humanity has always done so: through subterfuge, intimidation, and criminal acts. In essence, Trek has attempted depth by arguing its central conceit and showing it to be nothing more than a pipe dream.
There is just something slightly depressing about that. It’s one thing to show that victory will only be achieved through collective action instead of a magic space wizard, and that collective action, especially in war, will at times involve morally gray areas and downright unethical actions. That forces audience to grapple with the nature of war and what it means to fight even in an obviously righteous cause. But it is a completely different position to state that regardless of our emotional, technological, and social advances, humanity will always lean on its darker impulses to maintain control and progress whatever the costs. One is grounding and reflective while the other feels hopeless and suffocating.
I doubt that was the intentions of writers and showrunners, but I do believe there is room, and there should be, for shows and programming that remain hopeful and bright and demonstrate that humanity can evolve beyond its baser instincts. And that great and entertaining stories can come from that space. After all, they kind of already have.