That's not the argument. Never has been. Not in those absolute terms.
Contagiousness would be reduced if fewer people reached the contagious phase, if viral loads were less, if less contagious strains were more prevalent, if contagious people stayed contagious for a shorter period of time, or if people required a higher viral load to catch it. It's hard to know with any precision how a vaccine impacts any of these specifically with any precision because it doesn't impact all people the same and you can't readily collect data that does anything more than give you a a hint of one of these things in some limited case. You can look at aggregate data and say that some combination of these things is helping some amounts in some cases.
The difference between vaccinated people not spreading it at all, spreading it a little less, or spreading it a lot less is huge. Using wording that ignores the difference allows you to make a wrong statement sound right because it lacks proper context. Like saying seat belts don't prevent death in auto accidents therefore they are pointless.
You continue using the strawman seatbelt analogy, which does not apply.
In your own words it is impossible to know the degree to which the vax helps in any singular situation. Similarly, if someone has no symptoms but are unvaxxed, you cannot say that they are going to spread the virus.
You just stated in your own words why the mandate should not exist, yet you will deny this I'm sure.
Your mandates have done jack shit in stopping Covid in NYC. Just like the Social Distancing and Mask Mandates did a shit job in NYC the first time around.
How much proof does one need that the mandates are not accomplishing anything beyond discrimination and stoking anger between the political sides?
Not a single mandate has accomplishes a damn thing.
And of course Trump is still blasted for letting Covid into the US the first time around but Biden gets a free pass with Omicron. And no, I do not believe for a second that shutting down access to the US would have prevented Covid in either situation. The US is not New Zealand where it is easier to implement isolationism.
People just need to get over their freaking fear of Covid and death. Covid has proven time and again the ability to infect regardless of all the fear generated mandates. Hell, I know a complete germaphobe family that wears double masks and uses sanitizer 24x7, they social distance and only leave the house when absolute necessary...they all got it.
Stop the fear mongering. It's enough already. Yes, I get it... people are dying. But it is at a 2% rate. Oh, but the hospitals are overwhelmed! They cannot treat patients with "normal" issues. That is part of everyday life and death. A hurricane, earthquake, mass flood... many natural events happen that cause hospitals to be overwhelmed.
Omicron is something we should simply acknowledge, encourage, and move forward as best we can as fast as we can, and those who survive will pick things up on the other side of this whole thing. Cuz that is what we do. We get past horrific events. We pick ourselves up, support each other, and move forward.
Promoting an environment of getting through this together would gave been far more beneficial than adding to the increasing the rift in the political divide. Of course that would require great leaders in times of great peril, like Churchill and FDR. The time for arguing about which decisions were good or bad can happen after things are again "normal", but when in the thick of it everyone should be united. Instead we have had Neville Chamberlains in charge. By that, I equate both Trump and Biden to being like NC... dividers instead of unifiers.