and I have never slighted AA for doing any of those things, which I too have noted puts AA in a lot better position than UA, who is far behind.
Your point about growing the market by upgauging is the EXACT argument I have used about DL at LAX - with the difference being that DL can operate a much higher percentage of mainline flights solely because DL has no remote RJ only facility.
I have never said AA can't grow - and I expect they will win over traffic from UA at EWR.
But EWR and LGA/JFK are hubs for UA and DL and AA has a structural advantage of having a lot less to work with than UA or DL has.
In hub markets, size matters and it has been repeatedly shown that the bigger carrier gets a higher percentage of a revenue and disproportionately higher revenues.
NYC is a hub with duplicated services by multiple airlines; DL and UA serve most of the same domestic and many of the same int'l markets. AA does not.
Each carrier at LAX offers a significantly different offering of flights which cannot be duplicated by other airlines because there isn't space to do so.
AA can fight to regain some of the position it has lost at NYC. But they will always be at a structural disadvantage to DL at LGA and JFK.
That, like it or not, is the reality of the NYC situation.
DL uses more than half of the C terminal. US retains about 1/4 of the gates for their use. There are DL and WestJet gates on the opposite side of the same pier in C in addition to all of the gates at the security checkpoint and on the other C pier - plus what DL has in the D terminal.
And I have yet to see a plan as to how US is going to connect its services with AA's, esp. since the US Shuttle is dependent on connections while the DL Shuttle, which operates in the Marine Air Terminal by itself, does not connect with DL's other LGA flights.