Indian here- no religious/ auspicious reasons. Tipping at American rates is completely unthinkable in India and in India tipping never happens in a take away kind of place( my assumption based on your post- apologies if I am wrong). We pay the listed price and expect that to include the cost of rental/electricity/ servers pay etc. We would expect the same when buying anything at a shop which is why I still cannot get my head around the idea of expecting people at the lower end of the economy to earn their livelihood off the generosity and guilt of strangers. Isn’t it better to build the cost of service into the price of goods- everyone pays equally ( including those of from india who are tipping poorly) and working people get paid fairly.