Why don't I have a custom title by now?!
Not everyone can become a billionaire, no matter what hypothetical circumstances you propose.
I have one when everybody becomes a billionaire. It's guaranteed to work. Here you go:
1. Have the central bank prints a lot of money. Like, really a lot.
2. Send everybody in the country one billion in those recently-printed banknotes.
"But," you'll say, "if you do that then money becomes worthless!" Exactly. This is exactly what will happen.
You cannot be rich if everybody else is also rich. Wealth is relative: it is a measure of the discrepancy between the resources you own and the resources Joe Average has. You cannot become richer without making other people poorer. This is the cornerstone of the financial world. Some economists and politicians will claim this ain't so, that it's not a zero-sum game and blah blah blah. They're wrong, or more probably lying. The resources of this planet aren't infinite, so yes it is a zero-sum game.
We've been fed years and years of propaganda about how it is important to let investors and entrepreneurs go away with less taxes and less regulations because it's how they "create wealth" -- but you cannot create wealth without creating poverty. We've been told that the proper economic policies was to allow the wealthy to keep their money (rather than redistribute it via taxing and spending) because then it'd "trickle down" in a more efficient way than what the government can do. The result is a widening gap between the richest and the poorest (the rich become richer, the poor become poorer, the middle-class shrinks as they become mostly poor). More importantly, we've ran into a neverending string of financial crises.
Since poor people don't have money, they need credit. This allows fatcat bankers to increase their wealth even more because what the poor believe they own actually belongs to their bankers. But eventually, the scheme breaks down because you cannot get more money from the poor than they had to begin with, you can just sort of make it look like you did, for a while. Then the banks crash, go bankrupt, are bailed out by the state (with taxpayer money), the state gets a massive debt, needs to balance its budget by slashing social services, the poor gets poorer and need credit again, and GOTO 10.
As poverty increases, so does crime. The less scrupulous part of the poor, being denied a honest living, turn to a dishonest one. The lack of quality social services (including education, etc.) destroys the feeling of belonging to a nation, because you can't see your compatriots as your fellows anymore: instead, they are competitors, preys, and threats. The fabric of society is unraveled, people turn back to smaller communities -- clans, gangs, families -- for support and solidarity. Racism and xenophobia increases. Vandalism and aggressions become more common. Those who represent the nation -- like policemen, firemen, etc. -- become the enemy, since they work for something that you no longer acknowledge as being legitimately yours. Next step: civil war.
But hey, the 1% are ready for that. Why do you think there are all these gated communities being created? Why do you think there's so much research & development going into drones -- remote controled robots which will never disobey an order to open fire upon angry civilians?
But no. Welfare and minimum-wage guys are the problem. Taxes are evil. Greed is good.