How do anti government people expect the USA to exist without any government?

Anarchists don't understand the disorder they will encounter. Just as defund the police don't understand what they desire. No doubt government needs some serious attention but the lack of structure means simple things like: you made an attempt on my life with your bad driving so bang bang. Or even you looked at me funny, bang bang as gangs already exhibit with their anarchy.

In a Socialist world with no classes, no government and no countries, the USA would not exist. The world would just consist of people or working together for the common good. 

The point is for the USA to not exist. The funny part is that they seem to think this land mass would just sit here unmolested with a population living in some kind of survival of the fittest anarchy (as opposed to the reality that China would invade the moment the US fell). This is what you get when you stop teaching history in favor of teaching feelings.