The “living comfortably” part is a bit vague, but by any reasonable definition someone who is earning an average salary in a country which frequently appears in

The “living comfortably” part is a bit vague, but by any reasonable definition someone who is earning an average salary in a country which frequently appears in the top 5 of the various human development/quality of life indices is very likely to be living a good life. You can’t say the same for someone sleeping on a dirt floor.