While those are plot conveniences, it's still possible to create a good story using those tropes. In fact, some would argue that some of those tropes are what make Star Trek great. Good episodes have come from including the holodeck, Troi(yes, I would say that "Face of the Enemy" was pretty good), time travel and multiple-universes, technobabble, and Q.
Chekov's Gun can rarely, if ever, improve a story. While a lot of people seem to fall for Chekov's Gun, I don't think that those who are aware of it usually consider it to be a mark of a good story. At worst, it's obvious that the writer is bullshitting its audience. Chekov's Gun is just one of the many reasons why Abrams/Kurtzman Star Trek is basically on fire right now.
> - Multiple-universes time travel. Why stick with an existing world and its background when you can just replace it!
I don't think people are bothered by time travel plots because of the infinite possibilities to change the setting. They dislike time travel because it's usually too easy to travel through time, and shows or movies rarely adhere to any consistent time travel mechanics. Time travel stories are good at conveying high stakes, but they almost always lack any real consequences. When someone brings up time travel as a solution, nobody ever says "You know, the last time we traveled through time, we all nearly got killed and almost destroyed the universe."
A lot of good series have this "open sandbox" format where the context of the show is just a vessel for whatever story the writer wants to tell.
Examples:
* Star Trek Holodeck
* The various worlds in Sliders
* The infinite worlds in Rick and Morty means there are no limits to what can be written in.
* In Community, in a lot of episodes Greendale magically transforms in whatever setting is needed for the story: a court room where the murder of a yam is debated, a western/space battlefield where players duke it out for a grand prize, an entire city made of pillows and blankets, a zombie infested Halloween party etc.
The upside is anything goes, the downside is the perceived lack of consequences (especially in the extreme case of Rick and Morty).
>Chekov's Gun can rarely, if ever, improve a story
I guess I'd see Chekov's gun as a subspecies of a more broad range of tactics you can use to introduce themes and events so they don't completely come out of left field when the reader arrives at them. If you don't do this, you risk particular events appearing surreal - for instance, if a character shoots another with a gun, did they seem like the kind of person to own a gun? If so, you're basically doing a light form of Chekov's gun anyway, and if not, you either have to put up with the fact its presence is weird and jarring, or put a stutter right in the shooting scene, slow down, and explain why the gun is here. Seems very practical to me - when you require a gun, it takes about ten seconds to go back in the narrative and place one innocently in some corner.
Chekov's Gun can rarely, if ever, improve a story. While a lot of people seem to fall for Chekov's Gun, I don't think that those who are aware of it usually consider it to be a mark of a good story. At worst, it's obvious that the writer is bullshitting its audience. Chekov's Gun is just one of the many reasons why Abrams/Kurtzman Star Trek is basically on fire right now.
> - Multiple-universes time travel. Why stick with an existing world and its background when you can just replace it!
I don't think people are bothered by time travel plots because of the infinite possibilities to change the setting. They dislike time travel because it's usually too easy to travel through time, and shows or movies rarely adhere to any consistent time travel mechanics. Time travel stories are good at conveying high stakes, but they almost always lack any real consequences. When someone brings up time travel as a solution, nobody ever says "You know, the last time we traveled through time, we all nearly got killed and almost destroyed the universe."