Agreed. If a fat/obese person takes up more than 1 seat .. make them buy two seats and to BLAZES with any complaint. It is a comfort issue for passengers next to them and a safety issue for all the passengers and flight crew.
Too many two ton Tessies and the plane could experience substantial flight/safety issues.
That’s why I always... ALWAYS pick an aisle seat. The last time I was stuck in the middle between to chunky guys. I kept my elbows tucked in so close to my body to avoid touching them.