There's a good recent analysis of the hospital stats vs vaccination rates over time, amongst other things. But remember, our defense against viruses includes having infected cells kill themselves, so damage is always widespread over the body after a serious viral infection, it's just that the heart and lungs can't take time off or ramp activity down sharply to recover, so they're extra vulnerable. People dying days after recovering from Spanish flu and returning to strenuous farm work was common, for example. Two such cases among my grandmother's 12 siblings.

You're right re 100% infection by now. I had the first two shots (and two infections, one before vaccines were available.) But I did skip the next two, since the bivalent wasn't available yet and evidence re boosting with the same old vaccine was thin. (Antibodies are an indicator not the whole story.) Now I'm scheduled for a bivalent shot. The first vaccine doesn't really help with the new strain, says a recent study. (Google pubmed and you can really dive into the papers, and know more than I about it pretty quickly.)