This is an unusually glib comment for me, but it's something I've missed so much since leaving the northeast that I bring back pizza and bagels with me to Seattle whenever I visit New York.
The bagels specifically, are often doughy, "sweet" (they actually add sugar in many places), and with all the wrong textures. It's odd that you mention brands, since I typically buy "supermarket/local baker brand" but I've definitely found that to vary.
Similar comment for donuts, the big brands here e.g. top pot are practically cake rolls.
(Philly also had wawa and corner cheesesteak shops providing way cheaper "decent low-end hoagies" than I can consistently find out here.)
But I think that quality of an out-of-region bagel is also something I find in regular bread out here.
Also I infer from what is stocked on shelves and what I see friends and acquaintances buying that people here have much higher tolerance for stale bread.
Like the commenter above I was not seeking out these experiences, but felt like they kind of smacked me in the face when I got here. It used to be I could shop for bread without thinking. Now I need to be careful and sometimes shopping in the "wrong" place means I have to deal with worse options.
I have not noticed a difference in bread that you seem to have experienced. I buy the same brands of bread at the Safeway down the street as I bought at Stop & Shop in New England and whatever the grocery store I frequented near Seattle, WA. I never noticed a difference, but I also wasn't looking for one.
What am I missing that I have not noticed this stark difference in sandwich culture between the coasts?