Do you step out of your house at all? Because if so, you could be hit by a bus. It's statistically possible, right? Best not do anything if you aren't able to understand relative odds.

It lowers risk. Just like you do when you put on a seatbelt in your car.

You're still putting others at risk, that's someones family for gods sake. Stop being selfish and stay inside.

The goal isn't to entirely eliminate transmission, which is, as you imply, impossible. The goal is to reduce spread to below R=1 for the general population and any substantial subgroups.

And without the complete abolition of capacity to transmit the disease you're still a risk to that goal.

So many effective measures in the world aren't all or nothing, but still help substantially in managing risk.

60-80% reduced probability of transmission is huge. Sure, you're going to want to be careful not to go to a rave and then get on an airplane before visiting your immunocompromised relative for whom vaccination is contraindicated, and you might want to watch infection rates in your community, and perhaps even take other measures. But that's approaching an order of magnitude reduction in risk.

It doesn't matter as nuance and risk management has never been permitted to matter previously. It's still a risk. Lives are at stake and that's the end of the discussion.

Yes, but less so.

So, you're still a risk.

Risk is quantifiable. It's not a boolean. You are less of a risk for spreading covid19 when you are vaccinated for it.

It's a quantified risk until one disagrees with the belief holder and then it becomes a boolean.

You're less at risk but you're still a risk. Being a risk, no matter how small, has been the excuse for every response to this situation we've had so far and so this is no different.