Can I come up with a new one? Greek philosophers defined the world built out of 4 components. So, we doubled that! Either to point to Olam Habo (although not clear why it will be divisible) or just to raise the stakes!
Seriously, note the difference between Purim, and earlier malchuyot, and Chanuka: in Purim, we deal with a drunk Emperor who changes his wish every day. In Chanuka, we are dealing with _laws_ that prohibit things, a way more advanced civilization.
Why are we increasing candles? One big point of contention between Greeks and Jews is of statics v. dynamics. Greeks observe the world and accept it as is. Jews see history as a way forward and up, starting with sulam Yaakov and “chachamim yodea eitim” in Megilla. Jewish idea prevails in this debate, with Christianity, being a mixture of Greek and Jewish thought, accepting the history progress view, and so does modernity, including Marxism and all other isms that at least talk about improving human condition in some way.
So, increasing candles shows that we are always aiming higher.