The 5S was sold from Apple stores in India in mid 2017. So that's 3 years of updates from end-of-sale and this is an OS update for a 2 year old OS. So two years of support. Less than the Pixel.
When someone buy a 5S in 2017 they surely know already, or should, that it is a cheap buy to last less than a newer model. So 3 years in this case is actually a great deal.