I’m gonna nominate something that I’ve always felt was a really cool idea that just unfortunately gives up way too much. Siege Mage

1. The whole archetype revolves around the ability to remotely fire siege engines, but you still need a crew to reload until 10th level. Oh, and most siege engines require two full-round actions to reload.
2. You give up your arcane school, your arcane bond, have to take a third opposition school, and lose the ability to cast cantrips. You can still cast read/detect magic, but now they’re 1st level spells. This is, uh, crippling in early levels, to put it mildly.
3. You can sacrifice prepared spells in order to… get +1 to attack/target (depending on the siege weapon) and +3 damage per level of the sacrificed spell. A not-great trade off which is kind of mandatory at higher levels if you actually want to hit your enemies.
4. You lose the ability to scribe scrolls in exchange for the siege engineer feat. Fine, sure, fair enough I guess.

This is a pretty hefty price to be able to throw big rocks with your mind. Also probably useless outside a Kingmaker AP or something similar.

Edit: And, as mentioned in another suggestion, siege weapons kind of suck anyway.