In case anyone doesn't know, Oxyrhynchus is a major source of archaeological discoveries. Particularly ancient (Ptolemaic/Roman Egypt) papyrus fragments recovered from an ancient landfill on the outskirts of the city. Notably some of the earliest-known Christian textual artefacts were found there (the actual earliest fragments came from elsewhere in Egypt). It turns out that Egypt's hot and dry climate provides the perfect environment for their long-term preservation.
This is a common refrain but in reality I'm not sure it made much difference. Papyrus just doesn't age well and most manuscripts from this era would've been on papyrus.
What really decided what texts survived and what didn't was monastic traditions in in the Dark Ages and Middle Ages. At this time, a monk might spend their entire life transcribing a particularly long manuscript. The materials were also expensive. So monasteries were selective in what got retain and unsurprisingly it skewed heavily to texts of religious significance and then to texts of significance to, say, Roman and Greek tradition and history given that monasteries were European.
Cold and dry would be just as good. It's the dryness that matters.
The burn down of Alexandria library was a pity
What really decided what texts survived and what didn't was monastic traditions in in the Dark Ages and Middle Ages. At this time, a monk might spend their entire life transcribing a particularly long manuscript. The materials were also expensive. So monasteries were selective in what got retain and unsurprisingly it skewed heavily to texts of religious significance and then to texts of significance to, say, Roman and Greek tradition and history given that monasteries were European.