Uber's valuation is: http://www.wsj.com/articles/uber-valued-at-more-than-50-bill...
One might disagree with this valuation, let's assume it's 1/10 th of it. Can they provide health insurance to their drivers? Absolutely yes, but they're solely interested in revenue and being profitable. I don't want to sound like an Uber basher, this is true for most companies; they operate in their own self interest which they arguably should. It's up to the govt. to act as a counter balance to blatantly unjust policies adopted by companies.