The question is how much value should early adopters reap. Before bitcoins first halving, way back in 2012, almost half of all bitcoin were minted. Between then and the second halving in 2016, about another 25% of all BTC was mined. As of now, well over 75% of all bitcoin ever has already been mined, yet bitcoin has a market cap of around 42B - not even a third of McDonalds, which is around 130B.

If bitcoin ever were to become a universal currency, its market cap would need to grow into the tens of trillions. That represents at least a thousandfold increase in participation, and even right now 1% of all wallets hold 99% of the money. The richest wallet right now holds about 315 million USD in bitcoin. Is it truly reasonable that the person that controls that wallet, if bitcoin were to grow a thousandfold to encompass a large part of the global economy, be worth more than the current top four richest people alive? Wealth inequality is bad enough as is.

I think everyone can agree that it would be a disaster for bitcoin to take over traditional currency systems with its current design, where the total money minted ever is already almost all in circulation. By 2020 about 88% of all bitcoin will have been produced. That is just preposterous for anyone considering trying to grow it into a global currency of substance.