Because taxi's don't have a bloated 'backend' corporate office where thousands of engineers are making $300-500k a a year, and a bevy of extremely elaborate offices in the most expensive parts of the world, London, SF, NY etc. They have the dispatch company which runs on a shoestring budget and the cabbies who are either owner operators or work for a cab company, they also don't have the tech that powers Uber/Lyft which allows anyone to hail a ride from their smartphone. [tradeoffs]