"To protect everyone else" is not a non-answer, it's the actual real answer. You may not like it but that doesn't change the fact that that's how vaccines (at a societal level) work.
That may be true for virtually all of the common things we are vaccinated for but it sure ain't true for covid. The covid vaccinations did very little to stop transmission or even infection. I mean, if they did then why the hell did so many states bring back mask mandates even after 80% of their state got fully vaccinated?
The whole thing was just illogical nonsense forced through by people who knew perfectly well that if it was phrased as an individual choice, huge numbers would choose not to have it. Yet for collectivists (and public health is overrun with them) that's anathema. Everyone has to do it regardless of need otherwise they feel all icky.