Seeing that 90% of those in the ICUs are still the unvaccinated and many of them have been previously infected with Covid prior to Omicron -- it does not seem that prior infection is providing all that much protection in reducing the severity of your Omicron -- but the jury and science (studies, etc.) are still out on this particular point. Time will tell.
See, what is this "many"? Where is your source other than your ass?