I do not disagree with your point that the vaccine does not work on people who have an immundefect.

But that point was never in dispute, at least not in my comment.

Of course it would be great if the vaccine would also stop the transmission, but even if not, if less people get sick, less people will spread it, which will lead to smaller clusters.

It also allows the medical system to keep on working and providing the best medical help to people who do get sick.

Of course covid-19 is still an ongoing situation, viruses mutate, situations and recommendations change, but I don't see any indication that we can protect the population and even more the vulnerable population without a high enough vaccination rate.

Edit: Wording