Uber has no moat, so cannot possibly exploit a monopoly. The hardest part of their service to replicate is the drivers, and since they're all contractors they are free to work for Uber's competitors!
Even if Uber gained 100% share of car rides in an area, if they decided to exploit that by increasing their prices it would be relatively easy to create a competing company and undercut them.
Even if Uber gained 100% share of car rides in an area, if they decided to exploit that by increasing their prices it would be relatively easy to create a competing company and undercut them.