I wouldn't say salaries are better in India than SE Asia in general.
Just as glassdoor ratings are biased(given by folks who either loveee or hateee the company), same applies here.
People who have posted the offers much be pleased with the offer in general so it must be right skewed AFAIK.
Data will be a little biased, still i'm surprised at the packages being offered out there.
Salaries reported at glassdoor, linkedin, etc feel outdated.
I can see very similar numbers at https://www.levels.fyi/Salaries/Software-Engineer/India/ as well.