How it isn't? If they have the same evil intentions as the big FIAT holders of today, we are still screwed. Of course they couldn't (in principle) modify the way Bitcoin works, or could they? (by bribing the developers or whatever). There's also the posibility that big FIAT holders with evil intentions bribe the big BTC stakeholders for more FIAT, power, influence etc.
Still a lot of Bitcoins has to be mined so the wealth will be spread more evenly with time. And some early adopters big address balances are very likely lost, so cant be used anymore...
The number of bitcoins mined is totally irrelevant to how wealth is spread.
Don't think it will change much from where we're now, just the number of total users will be much higher.