I don't know what Uber pays their drivers, but I happen to know the place in question pays a good wage, comparably. I seriously doubt it driving Uber beats it.
>If it was a net loss for everyone except GrubHub or Uber, it wouldn't exist.
And yet, here we are. Econ 101 only takes you so far; why do you choose to ignore the other pressures? Once the econ brain worms take hold, people stop thinking.