From the introduction:
The witch is a powerful and versatile spellcaster, with arcane might rivaling any other class. With the option to select a hex at every other level, witches have access to a large number of potential builds, ranging from cursing crafters to cackling charmers.
If there is a downside to the witch, it’s that even when modified by hexes and archetypes, most witches end up with the same assumptions. They are always some sort of patron-inspired primary spellcaster, usually possessing some kind of familiar or tool, with a mix of offensive and defensive hexes best used outside of melee combat. In essence, every witch has a single archetype — the spellcaster.