The threat to book libraries from ransomware really is miniscule. 99% of all book libraries will backup to on a cheap removable usb stick or we card, which cannot be infected and held for ransom if stored offline. 64 Or 128gb storage probably costs less than single years subscription to a paid for anti ransomware solution and an offline backup is easy to update.
flipping it around, having your my documents folder protected from ransomware is little comfort if the rest of your machine gets encrypted.. you would probably have to wipe the hard drives and rebuild it all anyway if that happened.
Anyway multiple solutions and workarounds have been offered. The OP seems to have thrown her toys out of the pram and moved on. Maybe we should all do the same - move on that is , not throw toys
