This is because antitrust laws in the US have been reinterpreted by the courts to only apply where there is an adverse impact on consumers. In order to punish anticompetitive behavior that negatively affects workers in keeping with existing precedents, they get into redefining workers as consumers.

Is gig workers' poor treatment because of "anticompetitive behavior" or because they're low skill labor with plenty of other takers if one driver refuses the deal?

That depends a lot on the specific gig and market. To use taxi services as an example, in some metros Uber has completely taken over the market and can thus reduce driver compensation or add fees for drivers. Hidden fees in particular are classic anticompetitive behavior.

That very much seems to be the argument of the companies, doesn't it? Like, "Hey, we're just a tech company that has created a marketplace where people can request rides (for example) and people who want to provide rides can provide them. Both sides are 'consumers' of each others offers."

It seems like normally we see the government agencies bending over backwards to prove that is not the case, that these are actually employees working for the company providing the marketplace software, so this specific word choice in this instance surprised me.

(FWIW, as commentary, I had to insist quite strenuously in my own case that I had NOT been an "employee" of Uber or Lyft, even though I had been providing rides in the evenings when I had nothing else to do when I was new to town and wanted to learn what was cool and meet people. When I got laid off from my tech job, my state government was insistent that Uber and Lyft had also been "employers" of mine for the purposes of determining eligibility for unemployment benefits, until I eventually showed them I had my own LLC, corporate insurance policy, etc., because yeah, I was doing it as a hobby, but I was damn sure going to be running my own business as a hobby, not being employed by Uber or Lyft as a hobby. It's difficult for me to understand why people want to be considered "employees." You're much more at the mercy of the company that way.)

It's always about taxes. Most governments want Uber et al to write them a cheque for payroll taxes rather than hunt down tons of people individually.

That is the entirety of the argument around it.

Neither employees nor customers. I guess the underhanded fiction that is being pushed on us is that every gigworker is an employer.

If you get to be a small businessman due to your control over your own body, what is an employee again? Last I heard, employees also had control over their own bodies.

What is an employee?

a watered down version of a slave... the upside is that all the 'onwer class' can swap employees in an out. e.g. if the company is a carriage, the employees are the road for it. no longer does every carriage build their own road. in this sense the companies swap employes