the AA ad when they increased their Y class seat pitch a year or so ago
Yes, they are reversing the decision at the next main overhaul for a/c. The increase in pax numbers overall did not balance the books.
There is no limit to how cheap people want things to be. That is simple. If the lowest price has reached the point where you do not want to be cramped up, then you do not go.
The excessively cheap cost of flights in the 1990s is over. Fuel price and modern computer yield management have changed that. Folks got used to cheap and easy travel and I wish it could continue too but it hasn't.