Maybe it won't? I think it's unrealistic to assume that computer technology will continue to see the kind of exponential growth it has seen in the last 50 or so years. Of course, I don't have hard evidence to back up my claim but I feel like most processes exhibit diminishing returns after a while.
What you said would've been true in maybe 2002. However, the wages at these companies have been stagnant for the last two decades. They haven't even kept up with inflation. So no, $5k per annum isn't "market wages" for software developers in India. These are the lowest of the low. New grads in India often take these jobs as a last resort if they have absolutely no other option.