Follow the money.
How is it possible that a company can take over a government function and do it for the same or even lower costs to the taxpayers?
1. Their CEOs are more highly compensated than the government administrators who previously ran the operation.
2. The company is expected to pay dividends to stockholders.
3. The primary goal of the government was to provide a service. The primary goal of a company is to make a profit. The company pays bonuses to its executives based on how profitable they can make their new enterprise.
Taking the costs of the CEOs, bonuses, profits, and dividends out of the initial pool of money leaves far less to cover the costs of the actual service.
Corners will be cut to keep the profits intact. Some companies terminate staff outright. Some terminate staff and offer them their old jobs back at lower salaries without benefits. The quality of services will suffer. The frequency of services will suffer. Taxpayers will have much less power to lodge effective complaints.
Privatization is one more tool to transfer wealth from the majority of us to business owners and stockholders.