[robertlagrant]

Their existence isn't at stake. It's only at stake if there's only one employer, e.g. in the total opposite of a free market.

Your phrasing, e.g. "even richer than they already are" is really not helping. Anyone can start a business, even a tiny one. They take on risk. They need people to survive this risk. Those people want close to no risk, and a salary and other things. They get those not because of labour unions, but because these two types of people need each other.

[toyg]

There are so many variables, it's fundamentally disingenuous to say "just find another job". Maybe Tesla is the only car factory in town, and your skills are very specific to car manufacturing. Maybe you have a disability that makes it extra-challenging to job-hunt. Maybe you borrowed money to fix your home, and you can't afford to be out of work for a month as you look for another gig. Etc etc.

"The free market of labor" is anything but.