Except that they do, because they provide a level of flexibility not available at most other jobs.
If you're a college student and you have two hours and fifteen minutes between classes, you can drive for two hours and fifteen minutes. If you're a school bus driver who drives kids to school in the morning and drives them back in the afternoon but has nothing to do in the meantime, you can get in your own car and drive passengers at that time and make some extra money. If you have a part time job working three days a week with an inconsistent schedule set by your employer, you can drive another two days a week, even if it's a different two days every week.
There is value in that, or why is anybody doing it rather than working at Walmart or Starbucks where that isn't available?
But if you make the drivers employees then the company has no reason not to schedule their hours inflexibly, because the flexibility was only needed to attract workers at the lower level of compensation.
In practice what you're doing is disallowing employers from offering employees terms of employment that provide the employee with working conditions of greater non-monetary value than ordinary jobs in exchange for less money. There is no reason to think that this is never advantageous for the employee, and the workers who don't find those terms advantageous remain free to work for any other employer.
> When talking about jobs, especially in the US where so many benefits are tied to employment, a job with pay so low and no benefits should not be considered a good thing.
Then do something about all the benefits tied to employment. All of that exists only as a direct result of government policy.