I believe Bitcoin is a bubble, but I must point out that your argument is economically invalid. The maximum numerical total of coins (or units) that will exist is no barrier to use of a currency. If there are fewer units, each unit will just be worth more, to match the overall wealth of society. It only matters that the currency is conveniently divisible.
Bitcoin is divisible down to eight decimal places, not just two. So even though the price of a single coin is peeking over the $200USD mark right now, you can still spend as little as two ten-thousandths of a cent in equivalent USD.
In fact, the price of a single Bitcoin will need to reach $1,000,000 before the smallest unit possible will be equivalent to one cent in today's USD.
This is the same argument often used against gold as currency: "There is just not enough gold to support the needs of a population of 300 million much less a population of 7 billion." That's baloney. Of course there is enough gold. Each unit of gold will just be worth more, so people will have the same wealth, but just using less of it.
"And if some individual was to somehow buy all the gold then how much would they be worth?" Buying all the world's Bitcoins is about as realistic as someone buying all the world's gold.
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