It’s a problem that airlines will have to solve. In a world where people are no longer conforming to the one size fits all airline seat, something has to be done.
There are two parts to this, the airline should accommodate “passengers of size” where and when the can. I know certain airlines have started selling comfort seats, I think virgin Atlantic are one of these carriers that do. Also it should also be on the passenger, to be aware that if they do not fit into the one size fits all airline seat, to contact the airline in advance to make arrangements possible.
its not the passengers fault the airline tries to sardine as many people as they can into economy, but airlines also can’t make every seat custom fit.
i am in no way a skinny guy, but not overweight either (too many G&T’s in the lounge 😃
and I can find the seats down the back narrow at times.