my colleague recently took a ~79 mile uber from one airport to a location 1.5hr away, his Uber cost was <$88.

When you look at all the money going through Uber, fares make up 79% of expenses for that accounting period. But that's not the right number either. A lot of those expenses are other departments in the company. So fares are paying for more than 80% of combined driver costs, infrastructure, and marketing. Possibly quite a bit more. And that number includes all the cities where they are burning money to expand.

I don't know if fares are greater than costs in established cities, but I would not at all be surprised if they were.