Explain to me where libertarians are wrong?

Libertarianism is very naive. The ideology is based on a childishly simplistic understanding of the world.

Fun fact: Libertarianism originated with the anarchist extreme left, but was then embraced by the extreme right. That both the extreme left and extreme right get seduced by the same overly simplistic worldview shows just how divorced from reality it is.

The libertarian left thinks this ideology will deliver freedom from the corporations, while the libertarian right thinks it will deliver freedom from the state.

In reality, it will deliver neither. Strict application of libertarianism would quickly result in a societal collapse, which would then promptly result in some criminal gang or enterprising warlord taking over. So libertarianism cannot exist as a stable form of government, only as a transitional refime leading to even worse oppression than the failed forms of government we currently have.