PRO for fiat: Supported by the power of governments and all the elites.
CON for fiat: The elites have incentives to destabilize currencies by issuing too much, to receive unearned wealth and power. The more stable a fiat currency is, the more incentives to destabilize it.
PRO for Bitcoin: Limited quantity, can't be abused by the authorities, built-in anonymity to get around banning by authorities. Anonymity helps demand by savers trying to fight capital controls. The elites might one day peg currency(ies) to Bitcoin to stabilize their paper.
CON for Bitcoin: The elites do not want it to replace fiat.
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It is similar to war or gambling, where the future is inherently uncertain. IMO the biggest deciding factor will be geopolitics -- how well the Western elites can hold together a coalition of central banks to manipulate the values of various financial assets. If there is a major fracture, say, if China or Russia doesn't play ball, the Western elites might have to bow to reality and support gold and Bitcoin as a safety net. Of course the West is doing everything it can to put pressure on these two countries to make them toe the line, including using the news media, but the West is in a bad phase of its long-term debt cycle, and its power is not what it was.
Now the currency is enough in the market. Electronic transfers, credit and debit cards, online shopping. We offer services and Web Money and Yandex money and Kiwi. And it is unlikely the government of different countries, allow Bitkon reach their markets. Rather Bitcoin, and remains semi-legal payment system.