That's literally how herd immunity works. People with no or mild symptoms go out and spread the virus, people with heavy symptoms stay home. Virus is encouraged

That's literally how herd immunity works. People with no or mild symptoms go out and spread the virus, people with heavy symptoms stay home. Virus is encouraged evolutionarily to be as non-symptomatic as possible. Unfortunately we have totally broken this with our lockdown strategy, which has meant that heavily symptomatic people are allowed out to get medical treatment and spread the virus in clinic and hospitals, whilst everyone else is forced to stay home.