With respect-
I know what you mean when you say "government is monopolistic" but with a moment's reflection perhaps you will agree that- certainly in the US- it is an incorrect statement.
There is the abstraction called "government" which in its definition implies a singleton-ness- even this in practice fails the test because every US jurisdiction is overseen by multiple overlapping "governmental" authorities, and people interact with different ones often in conflict with each other all the time.
However the more significant objections to "government is monopolistic" are these:
In the "monopoly" sense there is literally no actual service in which any layer of US government is the sole provider. Mail delivery? Nope- UPS, Fedex, etc. Rule making? Ha. Contract law exists and in simple obvious ways even supercedes constitutional protections. Policing? Lots of private security around. Education? Tons of private schools around, including frauds that siphon public dollars while excluding public kids. Health care? Don't make me laugh/cry at the private predatory brutally expensive evilness that is so much of the US healthcare "system". Money supply? Nope, nearly all dollars are created and manager by private entities. Military? Also plenty of options here, none in any sense "well-regulated".
Which brings me to the "-olistic" suffix of monopolistic, which implies an intent to monopolize, a set of behaviors that prevents competition and the existence of alternatives to the singleton. In this way, as the above shows and which is plainly evident- there is virtually no domain in which the US government acts as a predatory singleton. The "-ilistic" is the most deceptive and incorrect sense of the statement "government (in the US) is monopolistic" because it simply isn't.
Amazon and Walmart, however- are defining the practice.
And when it comes to "nominal democratic control"- don't get me started. A responsive customer service agent is the devil's version of democracy. No thank you.
Cheers.