I'm not sure what it is, but lately the whole "airline partnership" business seems to be booming for airlines and doesn't actually help the people using them. We're trying to book a flight to Italy for September, and I'm learning way too much about how airlines work (or don't work) together.
American based airlines, especially Delta, United, and American, play this game where they offer Basic or "Cabin" economy. If it's not called "Cabin" it's something else that's non-descriptive. The Cabin Economy ticket will always let you select your seat, as well as be more flexible in case you have to cancel. American doesn't even bother to include any fine print that says, "If you're trip with us takes you on a flight operated by another airline, you'll be flying Basic Economy with them and will likely have to pay for seat selection." But that's what it should say. Our thing is... we're not going to cancel this flight. Sure, there's a chance we could contract COVID or something, but I see no reason we would need the flexibility of changing a flight, but whatever. However, I spoke to a woman at American just an hour ago to see if she could find a better flight than I was finding online. She hit me with one that connected with Iberia and told me the price of the Cabin Economy and made sure to say, "you'd get to select your seats free of charge with that!". I added, "not on the 10 hour Iberia flight, though." She said, "Oh... well, yeah, not that one. But your ticket is more flexible!" She didn't even understand how nefarious it is for American to offer 3 things at a $300 upcharge, but when one of those three things is taken away... the upcharge remains $300!
Seat selection is important to us. Mostly because my wife and I don't want to sit in the middle, and we don't want to sit apart. It's really a bummer that something as simple as selecting a seat has evolved into yet another scam the airlines use to pad their CEOs' wallets.