Your first links cite Veterans Affairs studies. VA patients differ in many ways from other populations and in particular skew OLD. Median age of all Americans i

Your first links cite Veterans Affairs studies. VA patients differ in many ways from other populations and in particular skew OLD. Median age of all Americans is 38.1yo. "The median age of veterans in 2018 was 65". What immediately jumped out at me from the third link was: "Median age was 64.5 years, 40% were Black, and 39% were female. 83% smoked within the prior year, 61% were overweight/obese, 83% had immune compromising conditions, and 96% had ≥2 comorbidities." Observational studies of specific elderly and otherwise at risk populations are unlikely to generalize well to the rest of us. There's also the issue of separating correlation/causation. Maybe frail people at high risk in general for complications are more likely to be infected multiple times rather than it running the other way. Your highly pessimistic perspective is at odds with what most of the rest us are observing and this quick glance at your sources gives me some suspicions why.