That's not how it works. Uber isn't operating at a profit because their current-investor-subsidized-rates are below the cost of their service. But there is a bit of a chicken-and-egg problem there: there rates are low because they want to gain marketshare, which is only enabled by the flood of VC/IPO money.
Eventually, all of the rideshare companies will need to raise their rates to cover the cost of service, and that cost should include reasonable remuneration for their workers. If it turns out the market isn't viable at those costs (i.e. if people just stop taking rideshares altogether because it's too expensive), then it never should have existed in the first place.