Your arguments read like you believe a DRM-protected ebook file is a verbatim copy that can be freely distributed and used. I just want to clarify that it is not, not even on a technical level. The form of DRM that libraries use is not just a license you agree to. It is an ecryption that turns that ebook into a garbled mess for anyone but the person who borrowed the ebook, during a set timeframe. After that period expires it cannot be decrypted anymore and stays a garbled mess forever, irrevocably ceasing to be a copy.