Would you prefer to have more of your damage bound to the covenant ability like Druids, Paladins and Warriors?
What happen is that all 4 abilities of Warlock Covenants are of a much lower budget on your overall dps than the likes of Convoke and Condemn, specially after Venthyr, Kyrian and Necrolord got nerfed to be on the level of Soul Rot during Beta.
Now, this means that Covenant Choice on Warlock is less restrictive than for something like a Warrior:
https://bloodmallet.com/chart/warlock/demonology/soul_binds/castingpatchwerk
https://bloodmallet.com/chart/warlock/destruction/soul_binds/castingpatchwerk
https://bloodmallet.com/chart/warlock/affliction/soul_binds/castingpatchwerk
This also means that what matters more is your Core Abilities and Talents, and not the Covenant Power.
On the other hand, you are less of a “One button” class than a Convoke Druid, Condemn Warrior or Ashen Hollow Paladin, and your Covenant ability feels less impactfull than other ones.
Personally, i prefer not being as restricted or bound by the covenant power, who is an system i haven’t liked from day 1.