They haven't implemented Pact of the Tome or Pact of the Blade yet, or the Archfey patron, so there may well be significant changes to the warlock in some future update (hopefully including the missing GOOlock ability in some form - if they think it's difficult to implement they could perhaps give an alternate ability on the basis that it was modified by the presence of the tadpole). And if the level cap is high enough, resistance to psychic damage is likely to be outrageously good in the endgame.
