Either you require some proof that you're not contagious to mingle with people or you don't. The reduced risk of infection from vaccination isn't the only facto

Either you require some proof that you're not contagious to mingle with people or you don't. The reduced risk of infection from vaccination isn't the only factor involved - go to a party with 10 sick (with Delta variant) people as a vaccinated person and see how it goes. IOW, I might have been staying safely at home for weeks before an event, while others might have been at night clubs every night. Who is more likely infected and why don't they need to be tested when they're vaccinated?