The question in my mind is whether uber is taking any risk in that arbitrage, if uber is essentially selling me "the rider" a swap (floating for fixed) it doesn't seem unreasonable they should be compensated for taking that risk
they are. If something unexpected comes up (say a high volume of traffic due to a sudden accident), then uber will have to pay the driver the higher amount.
I've always kind of wondered that, because I see the word thrown around so freely as a fancy word for "opportunity", yet its textbook definition seemed a bit more nuanced.