2013's Star Trek Into Darkness suffered from trying to be both a gigantic summer action blockbuster as well as a very self-conscious "reinterpretation" of maybe the most beloved of the big screen appearances of the original Star Trek crew. As a result, it didn't quite live up to either. You came out of it thinking that it was a bunch of individual little scenes that were kinda cool, crammed into an overall movie that was...pretty mediocre, really. It was worth one viewing on the big screen if you're a fan of space opera explosions, but nobody's going to be quoting dialogue from it in whatever has replaced social media in 2043.
The ambition of Star Trek Beyond was dialed back somewhat and, while it's no better from a snooty film critic standpoint, it's a better Star Trek story. It's like a classic Trek episode with epic CGI and lots of lens flare.
It's amusing because this reboot must really be a mirror universe: The odd-numbered films are the better ones here.