I don't see the fiat currency facing out at least not now and not in the near future. The massive adoption of the bitcoin and crypto technology won't stop people from using the fiat because they both have their own benefits and limitations.
People mightn't accept Bitcoin instantly because they're used to using fiats all their lifes but as the adoption goes on, people will used Bitcoin. Bitcoin can't shrink the economy but it'll improve it. Everybody owning Bitcoin will make them to have a different thinking about money and will become more functional to the society, be financially informed and not just a liability. Having Bitcoin makes you an investors and that's how people will begin to reason and it affects other things in life. I don't see anyhow having the thinking of an investor is going to shrink the economy. I'll improve it as people begin to invest in businesses and start up theirs making more job available for people to work, add value to the economy and everybody is happy. With more job creation, the economy will be the one benefiting the most of ias money keeps circulating in and out.
Traditional money thinking (spend, save, and occasionally the stock market) has held people behind for too long. Bitcoin alters all that. It makes you think like an investor. Now you're holding a growing asset instead of cash. You focus on the market, news, and technology. You become part of something greater. This is potent.
Suppose everyone has a stake in the game. Where everyone values long-term planning and responsible investing. We're talking about constructing a stable, successful future for everyone, not simply becoming rich. Old system doesnt work. Inflation, debt, and poverty are problems. Bitcoin offers escape. Take charge of your finances and develop something for yourself and your family. Yes, I believe. Bitcoin might transform the world. It wont happen overnight. It will take time, education, and people like you and me spreading the word.