If the government and banks hold 90% of bitcoin then the volatility of bitcoin will become static and the value will not rise for a long time. The market forces of demand and supply determine that price of bitcoin. The government will have to spend billions or trillions of dollars to buy that amount of bitcoin so its cheaper for them to ban than to undergo such an expensive venture
I agree with your opinion, the government must spend very large funds to be able to master bitcoin, so it is not productive. It is better to regulate or ban bitcoin in the country, where there must be benefits that can be obtained by the government in the short and long term.