How so? You can still get covid. Even the people vaccinated can get covid. Besides there is nowhere where everyone is vaccinated but you anyway. Some places have high rates some places have low rates. So your hypothetical situation just doesn't apply anywhere.

Anyway if you'd like an anecdote, I have a friend in Spain who just got the delta variant along with his 4 friends a few days ago. He was about to get his second shot yesterday (obviously it's postponed now) and his 4 friends were all completely vaccinated when they got sick.