Interessting opinion. I love playing warlocks (or multiclass combinations of warlocks and other charisma classes) in DnD and every time I pick Wyll I feel as if someone tried to create a weak warlock. I guess it's just a matter of playstyles.
But to be honest, combat in this game isn't really difficult anyway. So even if some subclass is weaker than another, you'll still be able to complete the game without issues.
