Having the old, infirm, and sick self-quarantine at home (like they do every flu season) would be a mitigation strategy.
A nationwide quarantine of all healthy people because of a disease with a 99.9% survivability rating is idiotic.
Do you genuinely think you're more equipped to answer this question than the vast, overwhelming number of professionals who disagree with you?
I would have hoped that with the benefit of hindsight and how poorly some of the posts from a month ago in this thread have aged, people would have taken a moment to reflect instead of doubling down ?