I seriously doubt those numbers. In SK with gas costing >US$1.50/L; a taxi driving for 20 miles would spend more than $3 on gas alone.
And Taiwan, $5 for a half an hour of driving is not going to remotely cover the costs of driving.
Taxi cab fares aren't high because they're gouging you; it's high because the cost of driving is high. Most Uber drivers, especially those with newer vehicles, are losing money on every passenger they take. The only ones who are successful are those that can game the system by cherry picking the passengers, work time, guarantees from Uber and drive a older depreciated and fuel-efficient vehicle.