A live action anthology series in the Star Trek universe would never be financially viable. One of the reasons you stick to a group of characters in the first place is so you can amortize the immense costs of sets, props, costumes, etc. over the course of number of episodes.
I imagine The Clone Wars
is able to cover so much ground because it is animated. The cost of frequent changes in setting would be much greater if the program were live action (another reason why the live action Star Wars
series has never come to fruition, no doubt).
There's a reason there are very few anthology programs on television and none (at least, as far as I know) on a major network: they're too expensive. They're also not great at cultivating a fan base, which don't have a group of characters to follow every week.
It's little surprise that so many of the few long-running anthology programs of the past thirty years have been based on pre-sold properties (Friday the 13th, Twilight Zone, Outer Limits) or recognizable brands (the feature film horror directors brought on to make Masters of Horror).