London, U.K. is about the same as Japan. I don’t have experience with India, and my knowledge of Canada is too far out of date to be useful.
All those salaries are very good for the local market, but are also much lower than SF.
All I can say, is in personal anecdotal experience, I make about the same money (with better hours!) in my current factory job than I would have if I finished my degree and went into software, and with none of the stress or crunch time or deadline associated. For example, looking at Glassdoor they have Google's Toronto office reporting starting salaries of ~$90-100k - while my base pay is only ~$62k ($29.50/hr) we get double-time overtime after 40 hours, I can (and have) clear(ed) well over $130k/yr with minimal effort.
They're offering decent salaries compared to other tech jobs in the area, but it's average-at-best if you start comparing unskilled labourer salaries in as a comparison.
I don't know anything about the income tax rates, but 65-70% pay seems like you'd take home more than an SFer being paid SF rates.