Actually it is known why epidemics grow reach steady state and then decay. .Its exactly the same as a forest fire . They run out of new fuel or people to infect. Even the more virulent infections rarely kill everyone , so a few survivors , .. survive. Otherwise the entire population dies and with their deaths, there is no more fuel, so the infection ceases . Sunlight , dessication eventually kills the viruses or bacteria. . Note some are remarkably long lived .. an occupational hazard for antiquarians and librarians is contracting TB from old books and manuscripts, as the TB produces spores .I was thinking about this yesterday and it's a little surprising that none of the experts one sees and hears on TV and radio have explained why Omicron will stop other variants from spreading. This type of thing seems to have happened in the past though, perhaps no one has come out and explained exactly how this works is because no one really knows.
I have read that after the human brain, the next most complicated think we know of in the universe is the human immune system. So it might be the case that nature will eventually sort out this pandemic for us, but we wont understand exactly how it has done it.
I think it was flecc who mentioned ages ago that sometimes pandemics just die out and no one really understands why, in the past we didn't have the genomic testing to be able to identify different variants of a virus. Perhaps in past pandemics something like an Omicron would come along but we were not able to identify it and that then would stop the raging pandemic.
This might be what always eventually happens which is why the human race has survived these things in the past. This is of course assuming Omicron is not has harmful as the other variants. If on the other hand the new virus is as harmful or even more harmful than Delta then we are in deep sh**.
Using Quarantine is the old fashioned way of protecting larger populations from the natural effects of serious contagions. If a disease is going to kill 10% of a population , it is better to ensure its only 5 out of 50 ships crew rather than 1000 of the population of Venice.