It’s not that Reaper isn’t fun. He is functionally bad.
Everyone likes to claim his damage as 140 per shot, one of the higher end DPS normal shots. That while armor does hit him hard not too bad and especially if he gets accurate hits and head shots. However don’t forget he has a pellet weapon, and no I don’t mean this from the armor view.
Do me a favor. Take Reaper, face a clean wall and shoot from decent distance. Count or estimate how much of his shot via bullet holes are outside his crosshair. Keep moving closer until all the holes are within his croshair. I don’t know the exact distance, but it is ridiculously short. That’s how close he has to be to get max damage.
After that, think about other characters models and hitbox compared to his spread. Even if you do manage good headshots, with his spread chances are you’re only doing 1/2-3/4 his damage anyways due to his large spread vs smaller hitbox on anyone that’s not a tank.
This isn’t even including that to deal even close to max damage he has to be in range of every CC in the game. Including two stuns (Brig & McCree), sleep(Ana), freeze(Mei), two-three knockback(Lucio & Ashe, Pharah).
Outside of this short range he is nearly useless. See how many shots it takes to kill a 200 HP hero with just Reaper from even medium distance. He has no way to get close without burning his only escape tool. Shadowstep may be the worst ability in the game. I can’t tell you how many Reaper I have noticed using it only to headshot him before he can move and usually kill him.
In his current state, Reaper is bad.
It’s not just one ability or an easily interrupted Ultimate either. He is fundamentally flawed.