FFlogs seems a bit wonky right now. If you look at the current raid tier as a whole, it looks like Reaper is quite a bit behind (5% behind the top, a little over 3% behind the melee over it), but when you look at it on a fight by fight basis, Reaper only ever seems to be behind the top dps by about 2% and is .5% behind the melee above it, which happens to be NIN which everyone is complaining is OP (which really was mostly just DSR being conducive to burst windows).

Also in all these cases, Reaper adps and ndps is either 3rd or 4th out of all 11 dps classes, so yeah it's plenty selfish enough, it's just that Arcane Circle and Circle of Sacrifice stacks throw off the perception of being selfish. For reference when it comes to Circle of sacrifice, assuming no one but yourself triggers it, you lose 245 potency every 2 minutes, less than one Weaponskill. A SAM that triggers Third Eye 3 times out of 8 possible casts gets more dps in that 2 minute window from something entirely reliant on fight design.