Some plausible reasons the drivers don't change jobs are (1) that RideCos offer the drivers paying work they prefer to their other realistic options, and (2) relatedly, that RideCos are more willing than other companies to offer the drivers work. Perhaps the drivers would have more good options if employment in other professions were not so heavily regulated. But (absent significant price controls) it seems like this is the sort of profession we should expect to attract marginal, low-skilled employees whose lives may inspire some sympathy, through no particular fault of the RideCos.