Sorry - this actually doesn’t solve the issue. The airline is charging more for larger passengers - but they don’t appear to be providing more space for the larger body, unless they have radically changed the configuration of their aircraft.
All this does is make a dent in their fuel costs - it doesn’t address the passenger space allotment at all.
I agree being 6’4” and 240 pounds, if I am going to pay double a 120 pound woman, I expect twice the space. I am sick of being folded up like a lawn chair to fit into a seat for 2+ hours. I have no problem paying extra but I expect my cubic footage to increase proportional to the charge.
A plane full of Samoans would probably hit it's weight limit with half the seats filled. Everybody gets two seats.
Problem solved.