Philly is horrible as a city, as an airport even as a hub.
The only reason it exists is because there was no competition for Usair and no slots.
As a city Philly is dying, there is no wealth, no industry or a highly educated population like NYC, Washington or Boston. Out of all the northeastern cities it probably suffers from the most despair. If AA can get rid of it they will and honestly they should.
https://youtu.be/Bi1Kf-1qd6Y