The USA is important, but not *that* important.

Even the British survived the end of the British empire, and that was bigger relative to the world than the US is now.

Silly argument. Empires rise and fall. USA isn’t the end of history. If USA sinks it won’t be great for the rest of the world but no not everything else will fall.

Sure but if the place you plan to escape to enjoyed protection of the falling empire before the fall things can go south fairly fast