If vaccines don’t provide immunity then what’s the point of all the public policy such as vaccine passports, etc? If you can still catch and spread it those who are vaccinated should be subject to the same testing requirements as the unvaccinated.
You're misunderstanding the precise use of the word "can" here. I can win the lottery. I can win a coin toss. But the odds are drastically different, and so en masse, we should plan and test much more for the "much more likely" case than the other. Now, vaccination against COVID gives better odds of not catching and not spreading COVID. You still _can_, though.
> If vaccines don’t provide immunity
But they do, statistically they provide a high level of immunity. Not 100% though. You know this: https://news.ycombinator.com/item?id=28699699 So why are you contradicting yourself?
It makes it sufficiently less likely that if everyone was vaccinated, each infected person would, on average, go on to infect less than one other person, and the pandemic would end. The more people who are vaccinate, the lower that average of "people that get infected by each infectious person" goes. That is why vaccinations are important to everyone, not just the individual who is vaccinated.
https://www.businessinsider.com/delta-variant-made-herd-immu...