no, if they in their offices put the exchangers crypto currency and will enter on them a percentage

Yes, bitcoin isn't now used for daily buys and sells. But there is a probability of being used for such purposes. This is what concerns governments and banks.

I don't think it is so now, but in some distant future this might become true.
Broadly, banks make money by issuing loans and placing deposits from customers as well as providing some settlement services, etc. and they charge commissions on all their operations. The commissions vary by country, but they're significantly higher than the cost of a transaction in BTC. Of course, banks will start losing money they used to have from their customers because in order to stay competitive they will have to lower the commission amount, etc.
So, BTC is not a disaster for the banks now, but it might turn out to be a disaster in the long run, I suppose.

cryptocurrencies are a disaster for the banks as they are decentralising the power away that the current democracies are trusting them with

No bank is being deeply affected by bitcoin yet, since the technology has not been adopted by enough people to make that kind of local or international impact, but as bitcoin becomes more popular there is no doubt that banks will begin to feel the pressure but right now the pressure does not come from bitcoin but from several business that are also offering loans to their customers.

Yes , local banks think that bitcoin is a big threat to . them. People nowadays choose to invest in bitcoin rather than banks. Bitcoin can now used to pay anything like banks but we all know that bitcoin is better than banks.

I believe that bitcoin is a threat to the banking system and the current economic system. And it's great, because the decentralized financial system looks much more promising and more subtle. If I am given the choice to keep money in the bank or buy the BTC, I will choose BTC.

We all know that bitcoin is very trustworthy and sustainable crypto currency and being in digital form, it comes superior to all the currencies available in the market and this is not theoretical, as millions of people in the world finds bitcoin much better, safer and the most profitable in all the terms than all the form currencies available in the market and no doubt that if crypto currencies will get legalised it the entire world then it will obviously decrease the use of Fiat currencies among people but I don’t think that this is also a threat to local banks as then instead of storing these Fiat currencies, they can start storing these crypto currencies.

I think it's like that. If Bitcoin and many subsequent projects succeed, the bank will not need much. But still a very strong few banks can survive.