He is injured quite a bit. 2017 was his one "healthy" year with 140 games. 2016 was his first full-time year and had 92 games, and this year he only has 28.
Coming from a Twins fan, Buxton's problem is that he can't stay healthy. Gets hurt, rehabs, comes back, gets hurt, rehabs, gets hurt while rehabbing, etc. If he can stay healthy and improve his hitting, he'd almost be comparable to Mike Trout. If not and his tendencies continue, Jake Cave could give him a run for his money.