The good thing about the 1918 Flu epidemic was that people got it and died (lots and lots), got it and recovered (a reasonable number) or didn't get it at all (most people).
Covid has us dealing with Long Covid, and we're still too early into the Covid Era to know how that will play out. Will it permanently impair a significant portion of the population? We already know that the vaccine doesn't prevent getting it, although the vaccine seems to greatly mitigate severity and death.
The history of this planet can be considered as a history of disease. We are the descendants of billions and billions of hominids (and even more billions of other ancestral mammals) who survived diseases. I'm sometimes astonished that any of us ever get sick. But we do. Vulnerability will always be present.
For what it's worth, I haven't gotten Covid so far. The initial vaccination, one booster, and I keep on meaning to get a second booster. I do sort of fall back on being the very healthiest person I know. Never get sick. Don't get a flu shot -- although I would never try to convince anyone else not to get one -- and last got flu in about 1973. Just turned 75, and I might well change my mind about flu shots in the future.