You had me up to that last part

Herd Immunity exists for the common cold, most likely it was a pandemic when it was first introduced into the human species

Herd Immunity has been acquired for the Spanish Flu, That's why it isn't near as lethal now as it was in 1918

Some are of the belief that the reason that Covid hasn't been more Lethal in Africa is because the overall population has been exposed to Corona Viruses in the past which is providing a certain amount of Herd Immunity

Herd Immunity is real and will happen with Covid over time

It's not going to kill everybody