Doesn't seem to me that a 1.6% host death rate would be much of a hindrance to its survival and spreading. I don't believe that the difference between past and existing variants' 1.6% host death rate -- and a strain (Omicron) with a (so far as we know) 0.0% host death rate -- explains more than a tiny bit of the apparent far-superior reproductive success of Omicron.
https://www.worldometers.info/coronavirus/country/us/
Edited to add - nevertheless, am glad to read that it appears to be a lot milder -- the below is more than one doctor's impression:
Early data from South Africa hints Omicron variant may cause less severe Covid, but more research is needed, STATNEWS, 12/4/21
https://www.statnews.com/2021/12/04/omicron-covid19-south-africa-data
Strikingly, most hospitalized patients who tested positive for Covid did not need supplemental oxygen. Few developed Covid pneumonia, few required high-level care, and fewer still were admitted to intensive care.
The report included an analysis of 42 Covid patients in the hospital on Dec. 2 which showed that most were actually hospitalized for other medical reasons; their infections were only detected because hospitals are testing all incoming patients for Covid. Many did not have respiratory symptoms. And the average length of hospital stay was 2.8 days, far shorter than the average of 8.5 days recorded in the region over the past 18 months, the report said.
The relatively low number of Covid-19 pneumonia hospitalizations in the general, high care and ICU wards constitutes a very different picture compared to the beginning of previous waves, said the report, authored by Fareed Abdullah, director of the SAMRCs office of AIDS and TB research.