This article is interesting, since it differs with what they said previously about domestic widebodies:
He
said that “if you have a wide-body plane, you bought that aircraft for long-haul flying… I can fly two [single-aisle] Airbus A320s or A321s for the same price as one wide-body on a per-seat basis. Economically, if I can offer two different schedule options on a narrow-body… that’ll be better for passenger choice than a single domestic wide-body.”
from:
https://thepointsguy.com/news/americ...-aug-sep-2021/
Speaking directly on the economics, it seems like they were able to actually use the widebodies domestically profitably. Whether that's specifically talking about DFW, ORD, and CLT to Hawaii flying, or the short ORD-DFW or DFW-LAX legs that I've done, or overall combined is unclear, but I'm certainly glad it's working out for them, as I love the lie flat seats, no matter how short the flight.