This video (https://www.youtube.com/watch?v=OEXJmNj6SPk) was recently published which shows drivers being offered the same gigs, but different payment amounts. Note that I could not find a published version of the data they collected in this video.
That is not explicitly proof of wrongdoing, but clearly algorithmic price setting can be demonstrated as not always offering the same payment to the same drivers for the same work. There may be a valid reason to why this is the case, but as the calculation method is closed source, the individuals being offered the wage are unaware of why they would be paid less than their peers.
This is work that is often considered "low skill" - which should actually make it extremely cut and dry as to why an individual would be paid more or less. Are they making their pickups faster? Are their customers more satisfied? If that's the case, why would they sometimes be offered more money than their peers and sometimes less money?
Almost all workers here are price takers, and suffer greatly from the information asymmetry present. Companies hiding behind "oh but the algorithm says..." is a poor excuse for inequality.
Edit: Because discrimination is in the title of the OP, I feel the need to clarify: in no way is the above saying that the video posted is proof of discrimination. Inequality need not be discrimination. When there is inequality without any measurable source, we need to be skeptical of the reason. Maybe one driver has better customer feedback, therefore they get offered a higher wage. There are many logical explanations for the result, but Uber/Lyft do not seem to engage with the discussion. This should raise red flags. That does not conclude that they are discriminating against anyone, and that would be a poor conclusion to draw without a true investigation.