In sci fi shows? It's purely because the writers don't want to show technology going beyond a certain point for dramatic reasons.
Trivial example - it's very likely that people of the future will have computers wired directly into their head, so you can control it with just a thought. In the real Enterprise-D the crew would never touch a control or look at a screen - they'd simply think commands into the wi-fi, and have images projected directly into their brain. Hell, there wouldn't even be a bridge - senior officers could teleconference from wherever they happened to be on the ship.
But whilst such things can work well in books, on a TV show it looks weird to show people sitting doing apparently nothing, so technology like this is almost never depicted.
Similar reason for all such limits. Why no serious genetic engineering? Because writers don't want to have a universe where people walk around with six arms, or gills, or are fundamentally different from you and me.
In universe, it's handwaved away by whatever they can come up with. Religious or cultural laws against certain types of technology is a common one.
Give a man a fire, and you keep him warm for a day. SET a man on fire, and you will keep him warm for the rest of his life...