Government by definition (at least through Hobbes' Leviathan) is the restriction of some freedoms through the monopoly of violence.

It restricts your freedom of robbing others, of killing people, of not abiding by a contract, there are many "freedoms" you don't have that are necessary for society to function.

As the other comment mentioned, markets != capitalism, capitalism is a specific system to exploit markets but it doesn't mean it's the best way that will ever be found to provide incentives to produce what society wants or needs.

Capitalism relies on a government enforcing its rules just as much as any other system. How do you think someone can own businesses, buildings and large swathes of land? Because if someone tries to claim them as their own, the government will come and restrict their freedom to do so. We also quite successfully restrict ownership of people these days.