I'm 6'-0", 260#, wear a 54" jacket, and have a hard time sitting in airline seats with the thinnest person next to me. My shoulders are wider than the arm rests.
I'm in the aisle seat, and the woman next to me, HAS TO BE my size.
Her husband, in the window seat, was probably 6'-4", 350-375ish lbs.
I spent the ENTIRE flight leaning out into the aisle, getting bumped by the beverage cart, or passengers going to the restroom.
MISERABLE flight.
Fly business or first class and you solve the problem. I used to suffer through economy class and then realized I was worth the extra expense to be comfortable.
I’m 6’5” and 200 lbs, so weight isn’t an issue but space certainly is. If I had to fly for any extended length of time, I’d pay for the better seats.