> what if it’s some landlord renting making a decision, some health insurance company deciding your coverage, etc.

Then you simply use the services of another private company. Here, in fact, there are no particular dangers, after all, private companies provide services to people because it is profitable for private companies.

This works only if none of those are true:

- There is real competition. It's less and less the case for many important things, such as food, accommodations, health, etc.

- Companies pay a price for misbehaving that is much higher than what they got from misbehaving. Also less and less the case, thanks to lobbying, huge law firms, corruption, etc.

- The cost of switching is fair. Moving to another places is very expensive. Doing it several times in a row is rarely possible for most people.

- Some practice are not just generalized in the whole industry. In IT tracking is, spying is, and preventing you from managing your device yourself is more and more trendy.

Basically, this view you are presenting is increasingly naive and even dangerous for any citizen practicing it.