Your chances of surviving anything are better the more healthy you are.
The odd thing about Covid is the extreme variation in effect is has in the population.
But this could be just a statistical normality for any "Novel" virus. I don't think we've seen a novel virus released into the human population before, or at least not in a long time. It's possible that in any population (human or otherwise), the blanked immunity (herd immunity) that a population normally carries, blunts the statistical extremes of an infection.