Do you think we have ORIGINALS or Greek or roman written texts?
We do have originals of some much older texts, though (cuneiform on clay that was fired after impression seems to be a pretty good archival medium, overall). We'd probably have a lot more original Greek and Roman documents if they hadn't been destroyed in wars and other disasters, or recycled for various purposes. There's a big survival rate difference between documents that receive basic care throughout their lives—no rough handling handling, minimal direct sunlight exposure, and some degree of temperature and humidity control in the storage area—and those left to fend for themselves. That's why old documents in surprisingly good condition sometimes turn up in caves, which tend to have constant temperature and humidity levels.
(But, yeah, current electronic media doesn't have much chance, with select optical disk media stored under carefully chosen conditions offering the best chance for your files being retrievable decades later, if you can find a drive to read them on.)