Earlier quoted context omitted.
avoiding exercise doesn't cause people around you to get fatter though.
And everyone is going to get coronavirus sooner or later, regardless of how vaccinated the population is. Because if the virus was stopped dead by vaccination then it wouldn't matter what other people did, and if it isn't then ... vaccines aren't going to stop you catching it eventually. Besides, there have been crazy ideas floated like making an issue out of vaccinating people who have already had & recovered from C…
I'm not sure if you chose this binary line of thinking or if it was by accident, but you present the outcomes based on a 0 or 100% efficacy when it's not the case.
It matters/ed what other people do, and if more people got vaccinated (or could do so earlier) it might've stopped covid. Whether it could now is a crap-shoot, but more protection is always better than less.