Typical Indian cities/towns are not very well planned (Chandigarh being an exception). Narrow alleyways, haphazardly shaped houses/neighbourhoods are generally the norm (especially in smaller towns). Beyond the backbone (which tends to be pretty good in general across ISPs), the main factor of speed of mobile internet, which Indians mostly use for accessing internet, is directly proportional to the reach of the cell tower to the consumer. I have seen excellent speeds in one room of a house and not so great at another room of the same house with Jio and Airtel.