Possibly because they're dramatically undercharging, loss leading, to get "market share"?
Undercharging, and drivers being paid "not very much" seems like two issues that are ... very much related.
I actually know of a system by which you could do that on a grand scale...for every single worker in America. Not just rideshare drivers!
It's a concept commonly found in a far away continent most Americans have only dreamed of one day traveling to, called "Europe." How it works is simple. You raise prices throughout the entire economy via taxation, and then redistribute that money back to the less fortunate via a government provided healthcare program.
...And here's the best part, studies show it ends up lowering the price of healthcare for everybody. I wonder if something like that might be a better use of our time than trying to put Lyft out of business?
However, given the system under analysis, because corporations have a history of making it very difficult for labor to be paid a fair and living wage, it falls to the government to use the tools at its disposal to ensure (as much as possible) that employees are paid fairly and have an opportunity to spend that pay on health insurance, because corporations won't be volunteering to do that, especially if they're already burning in excess of a billion dollars a year.
Because it sounds very unnatural for a social animal such as us humans to try to be completely self-reliant... We depend on others, we always have been and we probably always will, so leverage that instead of striving for some weird artificial sense of independence.