Whilst this is true, it's only part of the story. A vaccinated person who encounters the virus will reduce the amount of virus they pass on (thanks to the vaccination) so over time the amount of virus in general circulation will get less and less.
For me, I'll be getting the vaccine as soon as I'm offered it - to protect me and my immediate family, plus it will allow me to hopefully visit my parents with a clear conscience, knowing I've done everything I can to keep them safe (they got their shots today).
Plus, it's my small way of acknowledging the risk that the early vaccine volunteers took in testing the vaccine. They took that risk for the greater good. It would be churlish of me to turn down the vaccine "just in case" after all they did for us. π