If the government tried to force people to use a cryptocurrency to enslave people, it would be a federated chain, not Bitcoin.  Assuming the government didn't have diabolical motives, a government issued coin would probably be better than the system we already have.  You could delete the entire tax system and IRS, and transaction fees would be your tax that gets transported back to the govt.  The only problem is, they would eventually hyperinflate the currency anyway, so a government issued crypto serves no real purpose and couldn't compete with Bitcoin.