This is anecdote, but majority of the folks that Microsoft has on H1B from India are people who were hired in India in the first place and were allowed to move over because it was “worth it”. Microsoft specifically will be fine with Indian H1Bs even if they don’t want to pay $100k.

If it's so easy to recruit for the Indian office, why go through the trouble of getting an H1-B in the first place?

The timezone difference between the west coast and India is pretty brutal for close collaboration. Argentina for example is much easier.

Same reason why they go through all troubles to force RTO: to keep people around in the office to justify position of the manager.