Inferior processing can cause photos to age prematurely. That doesn't mean that you cannot find a good quality one hour photo processor, it does mean that you should shop carefully though. Whenever I want photos developed in one hour, I always seek out a one hour photo that uses the Kodak Colorwatch System. The Kodak Colorwatch System is a series of quality control tests that ensure a processors machines are calibrated correctly on a daily basis. Professional photos will be the most durable photos in your collection because they are printed on high quality paper that is unavailable to us a amateurs.
Photo paper can be acidic.
Any chemical that is near them that might interact with their chemicals to create a reaction can cause your photos to deteriorate. THAT is a very desirable condition. While photos themselves might be acidic in order to prolong their life, you do not want to ADD more acid to their environment.