You're absolutely right. The vaccine mostly protects you from having moderate or worse symptoms. It isn't certain that it prevents you from contacting the disease or being a carrier.
Which means you *might* still be a transmission vector to the unvaccinated. And there will be several flavors of unvaccinated. The "not gonna" crowd plus some people who will be excluded for various reasons (age, potential for negative reactions, whatever).
So there is likely to be a push for some time after mass vaccinations to mask and distance. I get it, but yuck.