But see above. What I pay the driver *has no direct relationship to what I charg...

But see above. What I pay the driver has no direct relationship to what I charge the rider (or vice versa). The financial metaphor breaks down here.

They correlate, sure: both formulas include miles and time (or estimates thereof). But they're not bound nor guaranteed to move in lockstep.

That drivers (or riders) thought they did is not a legal argument. (Unless they were led to believe false information by Uber itself.)