As for 'shelf-life'...seriously? There are a very few TV series still talked about 50+ years after they were created
That's kind of my point. Comparing Discovery to TOS would be very much like comparing Farscape to Buck Rogers in the 25th century (imagine, for a moment, that Farscape was meant to be a
reboot of Buck Rogers, as it easily could be).
Hell, even the direct comparisons between classic and new Battlestar Galactica ceased to be relevant pretty quickly. The new series eventually grew out of the shadow of the old and reached a point where it could be judged entirely on its own merits, with its own distinct fanbase that only partially overlapped with fans of the original.
Ultimately, trying to directly replicate BSG-classic would have been a loosing proposition. They took it, instead, in a radical new direction and tried to chase the untapped marketshare of "Not actually fans yet" and it worked. CBS is trying to do that now with Discovery; it probably won't work as well with the All Access paywall in place, but they certainly have the right idea.
If there's ONE franchise that's had a LONG shelf life it's Star Trek AS a franchise and TOS in particular
First of all, when I speak of Star Trek's limited "shelf life" I'm talking about the ability of the show to retain viewers and ratings over the long term, either in syndication or in the release of new episodes. That is to say, Trek series tend to go stale much faster than other properties. Partially this is because of an inability to "keep fresh" with new ideas and concepts, but mostly it's because a the MAJORITY of available Star Trek media is PAST material, rather than current or future material. To some extent, this is a feature of TV series in general: you can only get away with using the same basic story/set/design elements so many times before you use them up and people get sick of seeing them. Feature films do not really have this problem...
And yet, you just named three shows off the top of your head that already fit the bill, and you even overlooked many shows and IPs that DO. Mission Impossible, Transformers, Teenage Mutant Ninja Turtles, Pokemon, Macross, the Simpsons and Doctor Who, all of which continue to produce new series, movies and media on a fairly regular basis. They recycle old elements, sure, but they also introduce NEW ones fairly regularly, new styles of filming, new themes and new directions, and so on. And this for shows that have been on the air pretty much continuously in one form or another for twenty, thirty, even forty years.
How do they manage to pull this off? Well, in some cases, it's because of their format and storytelling mechanism make it really easy to totally reinvent themselves from one iteration to the next. Doctor Who, for example, is predicated on the idea that literally ANYTHING can change, so they have a fully integrated, fully in-universe reboot function ready made. Macross ended its first series with the (some might say ingenious) plot device and sending out a shit ton of colony ships all over the galaxy, so each successive macross series basically takes place in a whole new star system with a whole new cast of characters facing a whole new threat or a whole new KIND of threat; they don't have to worry about reboots, because if they write themselves into a corner or do something stupid (e.g. the
entirety of Macross 7) they can just set the new series in a different colony 60,000 light years away and mutter "Let's never speak of this again."
Other shows do it by simply not giving a shit about continuity. TMNT basically does a full reboot every five years or so, and Pokemon features teenaged characters that by all rights should be grandparents by now.
Star Trek series have, in the past, had a tendency to grow stale after just a handful of seasons. It seems this is owed to the fact that its producers have always been a little reluctant to try new things, and the new things they DID try were usually just retreads of old things (Enterprise is by far the worst culprit of this).
Yes, Star Wars is another franchise that will last and be retooled and rebooted and milked for everything Disney can get from it
Star Wars has never been rebooted. Not even VISUALLY. Think about that for a minute: the first cinematic treatment of Star Trek had to completely revise ALL of its existing visual elements in order to adapt the series to the big screen. TOS, in other words, had ALREADY gone past its shelf life and it was time to try something newer, bigger, more ambitious in order to keep Star Trek relevant. The changes they made in the first six films accomplished that... then the TNG films came out, and suddenly we found ourselves watching what were essentially feature length TV episodes on massively inflated budgets.
How does Star Wars manage to get away with using the same set pieces and the same ship design forty years later while Star Trek had to completely reinvent itself after only ten? It's because Star Trek series produce alot more HOURS of filmed material than feature films do. The pressure to stay fresh and come up with something NEW is that much higher for a series than it is for a film.
All of that being said: the worst thing a television franchise can do is try to run back to something it already did in the past. People don't watch new episodes to see something they've already seen in the past, they watch new episodes to see something NEW. When you start repeating what's already been done before, or doing new things in an old/predictable way, you loose your viewers. At that point you either change directions and do something new, or you double down on what you're already doing and accept eventual cancellation.
)
