At times it's also been one of the show's weakest links. It turns out, you can't solve racism in 50 minutes. And when you try to insist otherwise your show seems both preachy and naive.
You can see the franchise slowly learning this lesson, first starting to consider ongoing interstellar storylines in TNG and then basically just creating one incredibly long story in DS9, which is really what you have to do if you're going to wrestle with something like Israel and Palestine or you know, war.
Today Trek shows are on the surface a lot more fluid and nuanced; while DISCOVERY is clearly the child of the prior series and loves to sink its teeth into complex sociopolitical issues, PICARD can be more of a character study (see: The Title) with jazzy riffs and reexplorations of not just TNG but VOYAGER and potentially the entire pre-DISCOVERY Trek oeuvre. But it's also clearly looking at things like race relations.
Unlike its former iterations, it'd be very unusual today to get the chance to pitch an episode of TREK if you're not working on the show. But just for the sake of playing out the idea of writing for TREK, if I were to pitch a social issue-type episode, here's how I might do it:
1) TOPIC: BRAINSTORM AROUND AN ISSUE
Take a big issue in our world today--say climate change or the pandemic--and then just create as long a list as you can of issues that spin out of it. Don't self-edit and try to fill a full page with simple ideas.
Climate Change--The end of penguins; can't swim in the ocean; the air changes and makes pets feral; everyone has to take care of themselves; people fighting to live on mountains; bugs become deadly threats; societies purposely going to war or murdering some of their citizens to try and make the planet survivable for the rest.
DS9 clearly did this with Israel/Palestine and got a ton of great stories out of it, many of which were not the typical stories you read in the newspaper at all, which is part of what made it so exciting to watch.
2) STORYLINE: THINK BABY STEPS
Picking a good idea isn't about finding the most massive one. Honestly from the list above right away I'm excited to write about the end of penguins, something that hasn't really been talked about at all and that doesn't seem particularly significant in terms of our survival on the planet. But to me it somehow seems even worse, it's like the death of simple beauty or hope or wonder.
But of course you could swing for something much more massive, like societies at war to try and hold onto the resources they need to survive. But even if you do, you still want to think in terms of some one very small and specific result. Discovery is not going to show up and fix a climate change war in 60 minutes. It could very well try, but if it does it's either going to fail entirely (which can lead to some interesting stories about how they think about themselves and their mission), or there is going to be some one very small change.
If you're truly dealing with an intractable problem, any progress at all should be very very hard. You want it to feel like walking against a stiff wind. And if you do, even just a tiny bit of movement will seem like a huge win.3) THEME: THE OLDIES ARE STILL GOODIES
Star Trek has some really fantastic themes that pop up again and again. The Needs of the Many vs. the Needs of the One. Encounters with the Other (and its fantastic sibling, Encounters with the Other You have Imagined as a Monster). Realizations of one's own Monstrosity.
Those themes pop up again and again not only because they're preoccupations of Trek but because they're just evergreen topics and questions. And as we grow and change as a society, our very understandings of those questions change too. We see assumptions or ideas within them we didn't see before, and so there's new stuff to explore.
So yeah, never a bad idea to see if you can match a problem you want to explore with a familiar Trek question.
Another way to the same thing--rewatch some of your favorite Trek episodes, and see what issues they're wrestling with. You may very well find the thing you want to chew on yourself.