The second point, your worst case scenario doesn't even address the worst concerns of people who don't want to take the vaccine. They don't trust that spike proteins are the only things in the vaccine. The worst case scenario is not that the vaccine acts like the virus but that it acts different than the virus. And then you get conspiracy stuff like new world order types deliberately introducing things to the vaccine that will make it harder to have kids or stuff. And unfortunately our trusted organizations telling white lies to the public to elicit the behavior they want hasn't helped this trust issue.
But this is all moot for two reasons. First, because someone actually did a study and found that the immune response from infection was ~10 times stronger than from the vaccines[0]. Second, because we've already selected for a virus that is highly contagious and can infect vaccinated people, and will thus continue to be selected to specifically infect vaccinated people since most potential hosts are vaccinated at this point.
In summary, we might have to all be infected, nearly all at once, for this to be over, or just get lucky and the dominant strains will be attenuated to the point where they aren't a major problem.
[0] https://www.biorxiv.org/content/10.1101/2021.07.29.454333v1