Yeah. In TOS, they consider time travel to undo McCoy having a bad drug reaction, but in JJ-Trek it never occurs to them that they could go back and save the entire planet Vulcan. WTF? [Unless that movie takes place before The Naked Time, and nobody knew how to time travel yet in JJ-Trek.]
Time travel at will would make every consequential story meaningless. Not to mention it creates paradoxes, and it would undermine the existence of civilization because villains could go back to whack us before we invent the wheel.
Time travel produces the occasional gem like City on the Edge of Forever, Yesterday's Enterprise, and Trials and Tribbleations, but I have to silo those stories like
@Starflight suggests, or the whole ST universe is at risk.