I would like to note here that this topic is not for comparing "bitcoin vs fiat currency", here, the main goal is to discussing bitcoin as a unit of account in the future.
BTC can already be used as a unit of account bro, people don't even have to remove fiat from the equation, they just have to use it at a fixed price like back in the 1900s.
The dollar was backed by gold, and the value of gold was fixed, but it also pumped with time.
BTC has to replace taxes, debts, and salaries in order to start the change, but this is not enough to make a complete change. We have to use it for domestic buying and selling as well. But bro, you should know it has a scalability issue, we won't be able to pay the transaction fees on the mainnet.