If it reaches $1 trillion, what happens? $10 trillion? If it turns out everyone moves all their money over to Bitcoin because they're afraid of their fiat currency becoming worthless, how is that going to be a good thing?

Inflation of the dollar will skyrocket and anyone who wasn't holding bitcoin is going to get fucked. How is this going to end well?

Even for the bitcoin holders. If the economy is fucked from inflation and a car costs 50 bitcoins or $50 million of Fiat dollars... that's not going to be a good time for anyone.

The Bitcoin price will asymptotically approach its maximum - and the last people onboard will see the least amount of deflation.

It's certainly better money, and will have a lower monetary inflation rate than any other national currency by 2024.

It won't happen in a day. If your scenario is correct, economy will transition slowly to bitcoin from fiat. Fiat inflation is not a problem when you have non-inflated currency in a wide use.