You are overestimating the competitiveness of these markets. In many(perhaps most) parts of India, these operate as unions/ price cartels. The tuk-tuks in part

You are overestimating the competitiveness of these markets. In many(perhaps most) parts of India, these operate as unions/ price cartels. The tuk-tuks in particularly ignore meter pricing, in most parts of India, and may resort to violence/harassment to protect themselves from competition. Also most taxis/tuk tuks are independent and do not belong to any company. As such, I imagine they don't enjoy the benefits of economies of scale, efficiencies, and technology that Uber can afford. The quality of service is very poor, which makes Uber something of a Godsend. All these are points on which Uber can and is currently exploiting to gain a foothold, although they face strong challenges.