One female can get pregnant and produce one offspring at a time (typically), and there's a recovery period after delivery. OTOH, one male can impregnate an unlimited number of women, at pretty much any time.
For a moment, ignore monogamy, morality, etc. Think "caveman mode" for a moment, and realize that humans spent tens of thousands of years in "caveman mode" before civilization and religion and society developed monogamy. Our genes are still pretty much in caveman mode.
In that mode, a single male can keep ten females pregnant most of the time.
So from a population growth point of view, men could be 10% of the population and the population would still grow just fine. In caveman mode.
Aborting your female babies is how you do population control. India is, consciously or not, limiting their population growth.
What about "excess" males? That's what war is for. In caveman mode, at least.
Civilization is a recent, fragile, thin-thin veneer over caveman mode.
When cavemen did not have enough females they sought them out else where. This is what China is doing right now.
India cavemen will be forced to Bangladesh, Pakistan, or Shri lanka for wives. Then the whole process with start all over again of aborting females because you can’t fix stupid.
Regards,