imagine you want to buy an expensive gadget that worth $6000 and your spending limit on every bank account can't exceed $3000 per month.
If BTC payment become a thing then it will make a lot of sense, I can decide to spend $10,000 per day if I want or can.
Imagine you can spend as much as you want from your account without any restriction to the maximum limit of what you can send or receive into your account, id said it before now that the entire process in the use of fiat currency in the economy is very centralized and censorship is one of the serious challenges we have been battling with over the time.
In situations whereby you have a unit of account which you cant control or determine to what extent you want to make use of the fund you have, this laterally means the funds in the banks are not ours, but the governments hold them, since there are levels of restriction they share the authority with us and even override us in some aspect.