Theoretically true, but in reality, very few can sustain themselves for such a period without work, food trips, medical visits, etc...I got it, my wife got it, my son got it (but no symptoms), a good friend of mine got it a week ago. You won't witness sick people because they stay inside like they should. I have not run across any rapes or murders myself either, but they seem to happen without us personally witnessing them.
Only way to stop disease spread is to have everyone, everywhere, isolate for weeks at a time so it can't spread and dies out due to how long the virus can live. One person can infect a hundred or more by end of the day with how many people we come in contact with each day. Since we are still going around people, it will not end or slow much till the vaccine is out. Even then it will be around at the level of the flu.
If 80% can and 20% can't, the actions of the 20% will override the actions of the 80%.