The acquisition of bitcoin by newcomers in no way enriches earlier adopters, as in a classic pyramid scheme. Miners continually invest huge sums in capital equipment with the hope that the price continues to rise. If it does not, they are toast. This is not gambling or a Ponzi; this is just a risk/reward business decision. It's the exact decision that the capitalist makes when she decides to build a new production line at the factory.
Buying bitcoin early is like investing early in any new technology: it could be worth nothing, or it could go bananas. Many alt-coins have trickled down to very low prices over time or stopped functioning altogether. There are no sure things in this space, even for the early adopters.