n a hypothetical world where for example Bitcoin was so badly compromised that it can no longer function as a chain, do you think that crypto dies? ... Sure, it would be a public hit to crypto,...

The Peso took a big hit, there is still a peso. The ruble took a big hit, and yet there is still a ruble.If the American dollar took a big hit there would still be dollars, and some other token currency would step in to fill the void. It might be the pound sterling or the Yen or some other currency but one would fill the gap, just like if bit-coin took a big hit it could be replaced in the blink of an eye.

I am sure the IMF is all set and ready to replace the American Dollar with a Stable World Coin, should the dollar take a real serious hit.

Change never comes cheap.