Exposure to mold spores can be a major factor in the molding of bread, as can exposure to light, presumably because it helps the spores germinate or grow.
I was accustomed to white sandwich bread bread molding in 3-5 days sitting in its original bag on my kitchen counter. (We consume it episodically. Sometimes we can go through a loaf in a couple of days, other times it may sit there unopened for weeks -or until someone noticed it was gross and green.
At one point I decided to store it in a cabinet under the counter. My family didn’t adjust well to the change – they could never find it, and I ended up gettting them slices of bread when they wanted it. Suddenly the lifespan of the exact same brand of bread shot up to about 10-15 days. I presume that’s because I wash my hands dozens of times a day at work, and several times an evening at home, as the family’s primary cook.
I also found that those old metal slide-top bread boxes had a fair protective effect, possibly because they are opque and cool. (Also, my family "can’t find’ bread that’s in it either. I guess the box doesn’t fit their search pattern. Either that or they inherited my brain damage.) It does require a thorough cleaning once or twice a year to maintain that effect. I suspect that once in a while a bread bag has a hole in it, releasing spores into the box. The spores then get transferred to the outside of later bags, and to the indside by handling every time you open the bag and take a few slices out. Fortunately, those boxes are trivially easy to wipe clean
The source of the bread makes a difference. There are a couple of local grocery stores whose in-house bakery bread seems to mold in just a few days, while the same types of bread from other branches of the same chain last several times as long. I suspect spore contamination at the site. Since it affects the longevity of the bread, and not its wholesomness, and since moldy bread is considered a minor, inevitable risk, readily visible to the user, the store and local inspection board were not too interested.
Maybe “spore contamination” isn’t covered by the health code, or maybe they just didn’t believe me. All I know is: I am careful about where I buy my bread, and when I am forced by circumstances to break my own rules, mold usually develops much more rapidly than usual.
That’s not a direct answer to your question, but I hope you find it useful.