well, the government won't let this happen that easily. That's why currently regulations on crypto are very strict. It aims to ensure that Fiat will never be replaced. In some countries, even the use of bitcoin or crypto has become illegal. In my own place, bitcoin is prohibited from being used as an alternative payment because it will hinder Fiat flows, but the government allows bitcoin or crypto as an investment.
However, a lot of people know about bitcoin but don't know how to use it, so I think it's still difficult to do in general. Currently, you can buy goods, or use services by paying someone with bitcoin, but that only happens to people who know how to use it.
Not just your country, to date there are very few countries that allow the use of bitcoin as a currency or payment method. My country also doesn't ban bitcoin and we can invest in it but we hardly have any stores that accept bitcoin payments. Transactions using bitcoin or cryptocurrency for payment only take place when there is an agreement between the two parties, but that case is also very rare.
Also, what I wonder is, even if bitcoin were allowed by the government and used as an alternative means of payment, how many people would use bitcoin as a substitute for fiat currency? Most of us just want to make a profit from it, there are very few people who want to sell it so I think they will also hesitate to spend it as a payment method.