The likelihood of a text surviving tends towards zero given enough time

Before antiquity we often only have quoted fragments to look at

The early episodes of the History of Philosophy Without Any Gaps is a pretty good introduction to how little we know about pre-socratic thinkers especially

Surviving corpora can often be only hundreds of characters long

One thing to note is that there seems to be a compounding difficulty of preserving records. Eg we don’t have much science or mathematics from anything like late antiquity but somehow the Hagia Sophia was built in 537. If you look at the evidence that people were still capable of the kind of analysis required to build that structure it seems plausible that much mathematics or science was still happening (in the eastern Roman Empire) but not being recorded. Perhaps if you are copying books you’re more likely to be copying the important ancient foundational texts rather than more advanced narrower more recent things. There’s like 7-800 years between Apollonius and the construction of that church. I do wonder what mathematics was done in that time but not recorded. But it also may be that the culture around mathematics was somehow limited with no (evidence of anything like) algebra or calculus or coordinate systems which are pretty important to the developments in the last few hundred years of mathematics.

Early western Christianity was pretty bad for preserving ancient texts (a silly and likely exaggerated way to phrase the attitude is something like ‘if it’s compatible with the bible it is unnecessary and if it disagrees with the bible it’s heresy and should be destroyed’ though it also seems the New Testament is somewhat Aristotelian) but the eastern empire kept many of them going (in their original Greek), and the Muslims ended up with Arabic translations and Western Europe then got copies or contemporary Arabic works through what is now Spain and translated them into Latin (this could be somewhat tricky for mathematics but worse for anything more philosophical which would have likely been changed first to be compatible with Islam and second to be compatible with Roman Catholicism).[1] Eventually scholars in the west also got access to the Greek texts from the Byzantine empire and the attitudes towards censorship had changed (I guess it was less necessary for things that were not in the vernacular) and it was perhaps lucky that this happened before the fall of Constantinople.

[1] apart from destruction there are also things that are lost due to there being a lot of texts and not that many people looking at them. Eg I think there’s a big library associated with the bishop of toledo (maybe a cathedral or seminary library; maybe in a bishops palace) which is full of Arabic texts from before the rechristianization of Spain. There may be texts there which are unknown to modern scholars.

https://www.youtube.com/watch?v=CWu29PRCUvQ