I would say... in the LAUNDRY LIST of backlog repairs and updates SEPTA needs to make to their system, and the laundry list of new lines and new stations SEPTA needs (and the city and metro area needs) as well.... a subway stop at 22nd and Market has to be far down the list.
SEPTA is also cash strapped normally due to being criminally underfunded by the Feds and the state of PA, but is EVEN MORE cash strapped now thanks to COVID and decreased ridership.
Plus, my general rule of thumb is that if you're in 5 blocks of a transit station, you live close to a transit line and another station is not need.
Literally at 22nd & Market is a station for the Trolley lines. You can transfer from the MFL or BSL or Regional Rail lines to a trolley line.
5 blocks from City Hall Station (BSL), 15th Street Station (MFL) and Suburban Station (Regional Rail Lines) puts you at 20th & Market.
5 blocks from 30th Street Staion (MFL, Regional Rail Lines and Amtrak) puts you at 20th & Market SURPASSING 22nd & Market which is only 3 blocks from 30th Street Station thanks to the river........
If you can't walk from any of these numerous transit lines.... I don't know what to tell you