I am not sure that it is clear that to the "uninitiated" Omicron is far less deadly. While with other viruses for which we have an historical record, as you describe well, this is often the case, that doesn't mean it is going to be that way this time.
We are dealing with a different population now on the whole. Many people have been vaccinated, have had Covid at least once, or both. And 1 million of the most susceptible Americans are gone. And we have treatments.
I think it remains to be seen whether for the uninitiated, previously unexposed, demographic Omicron is less lethal.
Covid-19: is omicron less lethal than delta?
Death certification data support an intrinsically lower case fatality rate for omicron Soon after the omicron SARS-CoV-2 variant of concern was first reported to the World Health Organization on 24 November 2021, preliminary observational studies in South Africa suggested this highly...www.bmj.com
Omicron is also centered much more in the upper respiratory track and the original variants were lower respiratory and sometimes digestive. Infections of the lungs are normally much more lethal than infections that stay in the head and throat. People don't die from head colds, but they can die if they develop a secondary infection of pneumonia. My partner has almost died a couple of times from pneumonia that started as a cold.