Do you think it would be more fun if every character had something to offer to a Poke, Dive, or brawl composition? Reaper for instance works in Brawl or Dive, but not poke. If his teleport spot dealt damage, and was cancellable at any moment, he could at least bother people at range before moving in at the right time.
Not saying that is a change that needs to be made, it is just an example of how you could add a way for Reaper to fit into a team that is playing poke.
There are no metas or comps in most ranks in overwatch. Just chaos.