When done right, time travel stories are fun (ie "The City On The Edge Of Forever"), when done badly, well, they're bad. As far as alternate realities, they really should drop two of the three alternate realities from Trek (Kelvin timeline and STD timeline) and concentrate on the prime timeline, since it's been proved that good Trek can be done in the prime universe that doesn't need Kirk, Spock, McCoy, Uhura, Scotty, Picard, et al. Just look at Axanar.
STD timeline isn’t the same as Kelvin timeline. It’s either the prime timeline or no more separate than Ent’s third season.