Low cost of living leading to lower salary is one thing, but the cake is being able to exploit and overwork.
In India, almost everyone overworks. No exceptions. Even in most government positions. It is just what people are willing to go through.
No, it’s not "culture". Everyone hates it, but don't want to go hungry.
Another thing is, MNCs, both in tech and non-tech fields at least offers you a working space with AC and decoration. That's a big draw for many, if not most. As India is developing, many people are first generation white-collar job holders. They, and their parents are just happy that they don't have to do manual labor in the sun, or be subject to poor treatment by bosses in more traditional sectors. Such people will be unhappy, sad, and still accept the toil and pressure and overwork.