anarchism does not believe in any form of government. Libertarians consider that government is necessary in a civilized society. Each institution in society has a role and its own sphere - and these are what safe guard the society from abuse and exploitation by the other institutions. In other words, every institution has the capacity to become greedy and abuse its power because like the old adage, power corrupts and absolute power corrupts absolutely. Libertarians take the position that government ought to be small and balanced against the other institutions.
Having no government on the other hand leads to the abuse by the other institutions, such as private and elite wealthy power brokers, and also by religious groups.
These groups would simply and inevitable form their own police and armies and then we would have smaller states with their own governments trying to protect what they own. Again - this would lead naturally to some becoming big - and others forming allies. Some would lose. Anarchism is a pipe dream. As I said above - it is never a situation of hierarchy or no hierarchy - it is always going to be a question of who is the boss. In other words, government is inescapable. Yet, knowing this - and the corruption power brings, libertarianism works with the idea of separation of powers and powers with checks and balances.
The Left typically make the government bigger and bigger - with the dream pipe notion behind it - to get rid of government completely. Of course this has never happened and will never happen. Not for long anyway. Marx never really figured out how to from Government to no -government. Oh yes, he mentions the revolution. Violence. Peace.
But a bigger and bigger government leads of necessity to a loss in the power of the other institutions. And this leads to a reduction in the checks and balances. And this is in my view not only dangerous - but the autocracy of government. Which is really just another word for the concept "slavery of the people". Communism is ultimately slavery. And despite their objections to such a vile term - it is what it is. People must comply or face consequences. Individuals have no rights. Individuals become the property of the STATE.
Anarchy just gives the property of people to another person or state under the guise of fake freedom.