They can try it, but I don't think that anyone can ban crypto. Maybe we can try to think off some scenarios that theoretically could lead to banning and destroying crypto, but I think it's less likely that can really happe. Network is widely spread, you have nodes everywhere, and people will find a way to use it. And banning anything is always a sword with two sharp edges, banning and prohibiting can lead people to want it more, and if that happens due more risk involved it can lead to the price rise, just look what happens with other goods that were free to use and now they are banned.
Yes crypto is more good in this time especially this pandemic they cant use paper money because physical contact is prohibited, so we need crypto now, and also it is good in long term investment, they can't ban them because I think now, their citizen is already on it.