Many people still believe that Bitcoin can replace Fiat but I don't see it happening, it's not because of banks or this centralised world either.
People who still think bitcoin will replace fiat, the banking system while they themselves consider bitcoin as an investment, they also do not want to spend it. No offense, but maybe these people don't know what they are talking about, or they are just selfish people who want to get rich from bitcoin by holding it but encourage others to spend bitcoin and say this is how bitcoin replaces fiat.
We should accept the fact that we do not want to spend our bitcoins and that is the biggest reason why bitcoin cannot become a currency. Don't blame the government for not legalizing it and assume they are the biggest obstacle.
Furthermore , bitcoin is not suitable to replace fiat or banking because adopting a decentralized currency would only make it more difficult to manage and regulate the economy. This will make the economy more vulnerable to collapse.