The difference is much lesser 7-10x in big tech (Google, Amazon, Msft, etc). Big tech's Indian offices pays about 1/3 to 1/4 of what they would earn in the company's USA office. Levels.fyi will corroborate this.
Yes, while the average software engineer in India might earn 7-10x less than in the US, this isn't the case within major tech companies.
Pay in India is variable. They have a lot of great engineers who make good money - not what they would in the US, but the difference is not that much. They also have a lot of "engineers" who shouldn't be engineers doing the simplest tasks who may 10x less than they would in the US. If you just need a simple web app that is just like every other web app except with your logo you don't need the great engineers.
I think that your 3x difference is definitely a lower bound, and it'll be closer to 6.5x than to 3x or 4x most of the time (though I don't see aggregated data per-company, per-region in levels.fyi (but I didn't bother logging in)
