But there may be another currency that will be promoted by different governments, which is CBDC. If that happens in the near future, just as you say in 5 years, but maybe sooner because fiat money will depreciate because of inflation, that will be a huge problem for bitcoin and cryptocurrencies. CBDC will definitely become a worldwide ban for cryptocurrencies.
CBDC is essentially no different from fiat, the government can also print as much as it wants and it also loses value over time. The government issued a CBDC I think it will, it won't affect bitcoin, and they can't ban crypto outright if they have a CBDC. The value of bitcoin will always increase over time and people will gradually realize that with a constant supply only bitcoin is a good hedge against inflation.