Are those "more affordable options than San Francisco" affordable in a sense of raw dollar amounts or adjusted for compensation that software devs in London at

Are those "more affordable options than San Francisco" affordable in a sense of raw dollar amounts or adjusted for compensation that software devs in London at those startups would get paid? Because my gut feeling tells me it is the former (please correct me if I am wrong), and that wouldn't count as a proper comparison. Pulling made up numbers out of thin air to illustrate what i mean: let's say median cost of living in San Francisco for a software dev annually is $X and their annual compensation is $4X. Sure, it is nice that London is cheaper to live in at $0.6X, but I wouldn't call it "more affordable than SF" or alluring at all if the annual comp is $1.2X or less.