Especially after you factor in taxation. I live in Toronto, which is probably the second most expensive city in Canada, and I would rather earn 35k in northern Ontario than 60k here, even if the taxes were equal but after the taxes are taken into account it gets all the more crazy.
The only thing stopping me from moving to a little cabin in the woods is that I like to spend time around intelligent people interested in the same things I am, which is impossible in the boonies.
It is similar here in the UK, though without the regional tax variation (though there are some differences: if you have children in education, being from Scotland rather than England can have some significant advantages).
I live and work in York which itself isn't a chap place to live (both property purchase and rental prices are relatively high). I could earn more in other parts of the country, specifically London, but once you factor in the higher living expenses (or the travel time and associated costs if you tried to commute) a lot of that extra is lost and that which I would keep isn't worth the change at the moment (I like living and working in this area and don't like the idea of permanently remote working, and currently have enough job/career security that I don't feel like taking a punt on something completely new right now).
Similarly, there are places where jobs like mine pay less but the cost of living is lower - I know people with more money in their pocket at the end of the month than me because of this.
The only thing stopping me from moving to a little cabin in the woods is that I like to spend time around intelligent people interested in the same things I am, which is impossible in the boonies.