Then bitcoin will go to the MOON !!!
That is a completely wrong idea.
Bitcoins price is dependent on the USD.
If the USD crashes BTC is doomed.
Not necessarily. USD is not even the most used currency if we talking about bitcoin trading, Chinese yuan is. After hypothetical dollar collapse, there will probably be initial price drop of BTC.
But soon price will go up to even higher values than before, that is what most realistically will happen.
If the USD crashes that will cause other currencies to crash too, causing market and trading issues. This will cause people to go back to gold and silver.