Because you are paying that person money and have the ability to fire them. In the US you're also probably providing their health care.

I get what you're saying, but no one moves jobs every week. The sunk costs of switching employment are significant for the employee, less so for the company.

They provide you valuable work in exchange for that... Internally you are probably imagining some big corp that can pick from 100s of replaceable workers.

If you provide health care, you always have power over that person. Less so if they are relatively healthy - but any condition, theirs or a family members, means that the person has no real choice but to do enough good work to keep the job. Even if they hate the company. Even if you treat them poorly. They still must work for you. This is even more true if you have hundreds of people that will replace them and your health coverage is good enough - or at least, better than the opposition.

To a lesser degree, the same goes with vacation time and other benefits. At least in the US, anyway. This is why having some of this stuff coded into law and decoupled from employment takes some power away from employers.

Ideally there are multiple companies which you could choose from... And some might really need your specific skillset.

In practice, that's how it works, particularly at the lower end of the economic spectrum. If that wasn't the case then the concept of a minimum wage wouldn't be necessary - the market would take care of it.

Of course, this is a point of view and not everyone agrees with me, but to me it appears that for a chunk of the population the available jobs do not pay well enough to meet a certain standard of living.

> it appears that for a chunk of the population the available jobs do not pay well enough to meet a certain standard of living.

That is definitely true, but it's also pretty much the exact opposite of "always".