bitcoin will never be able to suck all the fiat money, they can just print more without problem
also fiat is already worthless, but you're obligated to use it for the majority of things
if you mean collapsed, i don't think so
how can it be worthless from now onwards .the whole global is running on fiat and some places accept bitcoins and other digital currency .and it is long way to go when fiat will become worthless.
Fiat is worthless. When government print it the value is automaticaly decrease, becouse of inflation. I am sure if bitcoin price reach $10.000 USD fiat will become worthless. When fiat value is decrease everytime bitcoin value is increase everytime becouse of deflation. So I think smart people will leave fiat and use some thing that give them benefit and safe their wealt. That is my opinion.
Smart people will use both fiat and bitcoin at same time at least for now to see the development between them.
You cannot just leaving fiat and go full use bitcoin , as you cannot do much with bitcoin in real life.
We don't what will happened but to anticipate something unexpected you guys better to have both .