But, if you watch the first season of TNG, it feels like there is a turning point where Patrick Stewart starts taking the role seriously (Symbiosis) and understands that he's depicting Starfleet as an institution and the restrictions (the prime directive) that institutions must enforce. The fellow actors also seem to take the series more seriously after that episode while before it felt campy.
It's clear he brought a gravitas to the role that inspired a team of young/new actors around him. As he later joked in Making it So, he once took things too seriously on set yelling "We're not here to have fun!" It became more than a job/role to him and in doing so he and the other actors inspired a science-inclined subset of a generation and brought Roddenberry's utopia vision to life.
That's a lesson everybody on this site should learn — Every senior is a leader, even if they don't think they are. People (mostly the more junior sorts) look up to you as a role model whether you (or they) know it or not, and that's very real power that you must learn how to wield.
I've given negative reviews to technically excellent candidates in the past because just about everybody in the org would look up to them if they got hired, and they would be a terrible role model.
Until dementia kicks in anyway
Dementia is a disease associated with age, not a result of age.
There was an interesting essay about Star Trek's depiction of society over time largely coming to the conclusion that modern writers/audiences don't seem to believe in the idea of duty to an institution.
https://www.thebulwark.com/p/are-we-all-too-cynical-for-star...
Similarly, Patrick Stewart assumed a written role, but he was responsible for its ultimate execution, which have him influence over the immediate execution in small ways, and likely, increasingly powerful influence over its future execution.
He deserves a great deal of credit for how Picard ultimately came to be represented.
Some of the other series and movies miss the point more dramatically for me by just becoming space opera. Star Trek was always political.
Though I'd say that Starfleet is in itself too "noble" to solve the problems that Special Circumstances solves in the Culture universe (though Section 31 isn't and they do feature heavily in DS9).
Frankly I think that Banks was smart enough to realise that if he want to have compelling narratives in a universe where you have near godlike AI's and everyone (including them) is nice, you need that edge somewhere.
Asher's universe which has a similar premise to the Culture (having come after it) solves it differently, some of the AI's aren't nice or even nice adjacent which also works.
In fact, pretty much all compelling pro-utopia fiction is almost invariably dealing with the fringes of such utopia - both because it avoids getting bogged down in the details of utopia (and risk valid criticism), and because there is no real substitute for conflict as narrative engine. So inevitably you have to go where the rubber meets the road, so to speak.