You missed the point where I was describing the Byzantine Generals problem, of which Byzantine Fault Tolerance solves, and BFT solutions are at the core of almost all blockchain protocols. Software imitates life.
There is no need for Byzantine tolerance when there is a single authority that is held responsible, like a bank, or a government.
Byzantine problems rarely occur in real life, they were effective invented by cryptocurrencies and "solved" by cryptocurrencies (by turning luck and wasrefulness into a measure of authority)
>There is no need for Byzantine tolerance when there is a single authority that is held responsible, like a bank, or a government.
Where do you live where a single authority that is held responsible? It must be a very idyllic place. In all seriousness a single authority is both very exploitable and failure prone.
If it was exploitable and failure prone, why is it the standard going back centuries?
If somebody gets into my bank account, what happens? The Bank covers my losses as law enforcement looks into the security breach and tracks down the thief. My life is unchanged, I don't lose anything.
If somebody gets into my bitcoin wallet, what happens? I lose everything I put into it, period. Can't get it back, can't prosecute, can't have my losses covered by federal investment insurance, it's just poof, gone, and no government is going to chase it down because the design of the system prevents any authority from intervening.
Which of these is more idyllic to you? I would much rather live in the world of banks and FDIC and police and courts than to live balancing on the razor's edge in crypto-land, a keystroke away from total ruin.