That’s the argument made by the Michigan Freethought group. As evidence, one member pointed out this article about recent work restoring a palimpsest to its original form. Seems the scrolls held copies of a bunch of Archimedes’ treatises and calculations originally, but some monks saw fit to rub and scrape those out and replace them with prayers in Greek. But with modern imaging techniques, we’re getting it all back now… Yay!