There are enough so that you can use them for one shots. But few enough that you don’t get overwhelmed.
They incorporate all the major skills between them. Their roles are well defined and align with genre expectations.
They appear in loads of the artwork and feel like a true part of the setting. Their personalities are communicated well through their beliefs, instincts and traits.
They give us the language to discuss in game situations with minimal set up.
I’ve not seen that with any other game. Not Mouse Guard, not Dungeons and Dragons. Pregen’s in Burning Wheel tie to a specific situation not generally to the entire setting or a central premise. And if you play Lidda the rogue or Jozan the Cleric in D&D you’re doing it wrong.
Torchbearer’s iconic characters are the best in town.
Varg’s skirmish-wise allows him to help in many conflicts that he lacks the skill for (mostly fighter).
Karolina’s field-dressing wise and Defender trait make her an effective ‘tank’.
Ulrik’s criminal skill and trap-checking instinct show you one way to multi-class in Torchbearer.
I have never seen pre-gen characters that teach you so much about the game.
I think Paizo did a really excellent job with the Pathfinder iconics. They evidently tried hard to apply lessons learned from D&D 3’s missteps regarding usage and diversity.
I consider them a close second to Torchbearer’s. But yes, Torchbearer has the best iconics.
I also think the iconics for the memento mori books are phenomenal. They make me want to play those classes.