Are you looking for 100% effectiveness? That's not how anything in the world works. If I can reduce the probability of spreading infection, that is a clear benefit to society. If enough people reduce the probability of spread enough, we can reach a point where for all practical purposes, the virus is gone.
No one is realistically looking for 100% effectiveness. However the vaccines don't reduce spread enough to eliminate the virus. Eventually we'll all be exposed. The main benefit of the vaccines is preventing deaths.
