Leave broadband, the mobile data rates and caps are exorbitant in US-CA. Back in 2016 I was paying $5.5 for 10GB 4G data in Delhi, and in US its like $10 per GB.
It's certainly not a factor of 40, but at 16x it's still quite significant. I'm pretty sure the population density which is 10x higher can factor for the 2.5x remaining.
[1] https://www.payscale.com/research/IN/Job=Telecommunications_... [2] https://www.salary.com/research/salary/benchmark/telecommuni...