I don't understand why the USD can rise so high.
There are many factors that affect the strength of the US dollar.
One of them is what you already have mentioned. When another nation goes under crisis, they will try to look for other ways to save their money or multiply it even under crisis. Typically they will buy assets that are sold in US dollar hence why its value goes up.
Does this also affect the decline in the crypto market?
Fiat specifically the US dollar are kind of the opposite of one another.
If the US dollar is so strong and it is what is used to buy crypto, then not many people might be so inclined to buy crypto with USD.