Network effect, first-mover advantage, and fair launch that did not pre-mine coins for insiders. It's the only "pure" one because it was first and honest.
Satoshi ninja-mined in the beginning for themselves. If they had posted about Bitcoin further in advance and had many more people mining, that would’ve been different.
Every human endeavor since the beginning of history has had some form of information asymmetry. Not everyone can be lucky enough to buy AAPL in 2001 or BTC in 2009. Apple management and Satoshi both announced what they were doing publicly to anyone who would listen, but not everyone was listening. Unless you can conjure up a method to deliver every piece of information globally to everyone on earth instantaneously, you'll just have to accept that as a fact of life. It's not bitcoin's problem to solve. Complaining on the internet about how life is unfair certainly won't solve it.