Stumbled into this comment recently made by Alexander Macris, creator of ACKs, was asked to describe the difference between ACKS and 5e:
5E vs. ACKS: 5E offers your character more abilities in a game, ACKS offers your character more power in a world.
5E does not assume that there's a world that exists that follows the rules of 5E.
ACKS assumes there is a world that exists that follows the rules of ACKS.
The reason 5E's realms aren't overrun with a demographically-appropriate number of 20th level wizards with armies of dragons is that those wizards simply don't exist, and the game doesn't think they should.
If you've ever looked at some of the peripheral ideas and rules thrown about in Axioms, or been privy to some of his rule discussions on how he factored in weather patterns for the Auran empire, this is a guy who cares about the world you're playing in making sense.
Your choices matter. Not because you're a special snowflake viewpoint character so of course they matter, but because you're playing on a field with everyone else who has to follow the same rules. It gives you the tools needed for your place in the world to matter.
That map up above? Alex spent time calculating out if there was enough storage space for the feed for the horses in the local guard. That same effort to make the world work reasonably around the character as everything else gets weird shines through.
