See, but that is exactly the problem. Set bonusses and legendarys should not be mandatory to make a spec competetive. And while DH is totally fine in M+ it is a disaster in Raids, because Single Target ist just too weak (without the ring).
They made the same bullshit with fury warrior in the last addon, who was bareplay playable because you were rage starved all the time for half of the addon. Then they added set bonusses to fix this and adjusted the damage ouput and it was "fine" as long as you had the set bonus.
But at least from my point of view that is really not how a class should be designed.