Actually even more complicated than that. Say we adopt the personal liberty premise. If I am at high risk, I stay in my house and have everything delivered etc.

Actually even more complicated than that. Say we adopt the personal liberty premise. If I am at high risk, I stay in my house and have everything delivered etc. Then my furnace breaks in a way I can't fix, and its winter. If I don't want to freeze to death, I need to get it repaired. If the repairman was willing to "take their chances", I could be forced into exposure and infection. It really is a group activity - individuals can not take their own risk without risking the lives of others.