That's true, new variants such as Delta and Omicron are causing a high surge however according to many studies, the data shows that even though Omicron is more contagious, the variant generally has mild cases, a very small amount of severe cases.
I'm not sure if the unvaccinated spread the variants more than the vaccinated. In the highly vaccinated nations where covid is surging, the cases among the vaccinated are higher than the unvaccinated. For example, The Canadian province of Ontario is over 75% vaccinated and according to a recent daily report of covid cases, On December 21, 2021, 3,453 new cases were recorded, the data showed 673 were unvaccinated people, 132 were partially vaccinated people, 2,500 were fully vaccinated people and for 148 people the vaccination status was unknown. So cases in the fully vaccinated are actually higher than the unvaccinated.
Here is the report from Global News: According to this recent daily covid cases report from Global News: https://www.google.com/amp/s/globalnews.ca/news/8465326/ontario-covid-cases-december-21-coronavirus/amp/
I think the reason why people want to believe that the vaccine makes it "impossible to get covid" is to have a false sense of security and a false sense of control over the situation, kind of how they hoard toilet paper. This mentality is deluded and I would probably even say dangerous. They need to face reality, learn that somethings are beyond our control and everybody gets sick at some point, it's a part of life but getting sick doesn't automatically mean "the end of your life".