He’s fine as a stand alone threat in a lot of situations where you’re trying to close out the game, I take him on the 2nd point of control maps in order to flank and open with a pick while sustaining thru’ respawns or on the retake to get a pick and then stall out.
One of the things most people don’t think about is the value of their base kit and the rate of their ultimate charge going into the last fight of the game, it’s a big reason you’ll see a Genji swap off for a Doomfist, a Zarya swap off for a Roadhog or a Sombra swap off for a Reaper etc. in the last minute.