Hmm, a controlled currency would not be possible, as bitcoin is not owned or made by a single institution. Unless Bill Gates, Warren Buffett and the Koch family would buy
all available bitcoins (which would be nice for the current owners of bitcoin as this will cause a massive price increase), bitcoin would not be a controlled currency. Oh, and by the way, even if somebody would buy them all, the market is gone, no users are left and BTC will probably be dead.
So, a state-controlled currency to replace the dollar? No, It is by nature a deflating currency, not inflating like paper money. Nations will hate it? Yes, their power to print money will be gone. As more and more people around the world will understand that our current money system works, but is corrupt, and bitcoin is not corrupt by its nature due to its maximum emission of bitcoins, the world will flourish.
Haha just imagine (this is probably nothing serious for at least the coming 50 years or more): Billionaires of this time (dollar time) will be the ones having 7,2 bitcoin, as Bill Gates has 72 billion right now. We will look up to those persons and be like, wow he has 7,2 bitcoin! He is a the richtest bitionainre in the world! (haha.. bitionaire sounds like bitchionaire, maybe bitlyionaire is a better word choice). The poor ones among us are begging on the streets, asking if we can tap their phones using NFC to give them a Satoshi or 5... What a strange world that would be
Maybe some will look back at this paragraph in 50 years and think haha, he was right after all.
Somebody else's thoughts please on this topic, I find it interesting haha!