When you say control, you mean the government has the power to devalue crypto by making it infinite? Isn't that also possible for other cryptos made by companies?
The government will have full control over everything. Supply, addresses, inflation rate, transactions.. Just like banks function today, the digital currency will. The difference is, today you can purchase an item worth $5 using cash without the government knowing you were the dude who's purchased a condom. There likely won't be a possibility to keep it on a Ledger - and even if there is, there will be the possibility that your coins will be seized at any given time if the government wants to.
The currency's price will be stable. Don't imagine a CBDC created by the US would explode past Bitcoin's price due to adoption. No, it will most likely be pegged 1:1 to the USD. We won't give it value. It's still the rich and the bankers who will
Yes, it's possible for other cryptos created by companies too. Once a blockchain is centralized, its users are no more under control. Instead, the control falls into the hands of the coin's creators.