Do the other human coronaviruses (OC43, HKU1, 229E and NL63) exhibit what you call "herd immunity"?
No, they don't.
Why should this one be different?
Fair enough, but why do different strains of corona influenza go away, plus some colds that are corona and not rhino also go away? Why did the Bubonic Plaque finally go away when there were no safe-guards nor therapeutics? There were still plenty rats and lice to infect humans to die.
Let me tell you a conversation with my Daughter-in-Law (35)and her verified case of Covid. She had some flu like symptoms for 10 days and I just talked to yesterday via phone chat. She has now tested negative and is feeling great. So is her best friend (35) who was on the call, besides my Wife.
You can be right, but we have done more damage to our economic system than any of the deaths incurred. You know the damage, so I won't itemize.