There are exceptions to this of course, such as government-sponsored monopolies (healthcare, ISPs, utilities). But a lot of that is regulatory capture IMO - we've ceded a lot of power to MegaCorp Inc. which I'm not comfortable with either.
As terrible as a lot of big private companies are, at least they can't waltz into any/every platform (e.g. G, FB, Twitter, etc) and demand everything they have on you like the feds can. No one holds a candle to the potential of govt tyranny, everyone is at the mercy of "the man".
At the end of the day, massive consolidation of power at the top levels of society is never healthy, whatever form it may take.
This in an amusing statement considering that many people consider Google and Facebook to be terrible big private companies.
And note, their power doesn't come from government-sponsored monopolies.
Also, calling utilities and ISPs government-sponsored utilities is grossly misleading; both are natural monopolies due to the capital costs that are involved.
Capital costs do not create monopolies, just an obstacle solved by raising capital. Government regulations create monopolies - there is no way to fix those.
People believing in the so-called natural monopolies lack fate in the entrepreneurial drive, creativity and innovation of the free individuals working hard in their own interest, for their own betterment.