There is a trap here of saying "thus we shouldn't do anything about problems" rather than the more reasonable "we should be prepared to iterate on our efforts".
This forum seems to be filled with (comments by) people who love the "there's no perfect solution so we shouldn't try because trying might infringe on my libertarian liberties". I need to stop reading the comments.
It’s more a criticism of top-down hierarchical control of institutions (at any scale) than it is an indictment of humans cooperating around some goal
But note how all the examples were private companies or enterprising individuals who weren't controlled somehow, but simply wanted to protect their profits.
The political right uses multiple deca-billion-dollar megaphones to talk nonstop about this problem as it relates to the government while dramatically underrepresenting the extent to which it happens in the private sector so that they can lobby for privatization as a silver-bullet. I think it's fair for the article to shore up the complementary point of view. No less fair than what the right is doing, at any rate.
Private ownership of land and capital is also enforced at the barrel of a gun, lol.
When monopolies are common, every business school student openly aspires to rent-seeking moats, and regulators snore more loudly every day, the claims that the private market is checked by competition frequently ring hollow. The big difference between public and private sector is that the private sector has literally entitled themselves to this rent seeking behavior, while it's only a metaphor in the public sector.
Don't get me wrong, I think competition is a brilliant principle and I think markets are the place to make it happen, I just think that strong anticompetitive forces are common natural occurrences in free markets and I think that the government should play a stronger role in checking them.