"Why would you want to match to DL to start with other than moving to a hub city?"

It's a totally fair question. I'm NYC based and have watched AA's presence in the region deteriorate while DL's has grown into a real hub. I held out hope for AA through the JetBlue/Northeast Alliance, but with that gone I really feel that I need to make a switch.

It's going to be painful to go from AA EXP to DL Platinum, particularly under the circumstances you outline above, but I'm really not sure there's another pathway. I expect I can make the Diamond spend in 2024.