It's not "cheap" if you cannot take a ride. Total cost is a sum of the price, time wasted and the risk of being late. "Cheap" taxi that is impossible to catch is not actually cheap.

That's the same fallacy as when people whine about Uber's "surge pricing". When there is huge demand, Uber prices may go up 2x, but you still will be able to get a ride in 5 minutes instead of waiting half an hour or not even knowing if you will be able to catch a car at all.