I don't know the stats behind it, but I've heard from news that those with the vaccine do still host the virus when exposed and even continue to pass it along (although they experience lesser/no symptoms).
If vaccinated people do become infected at the same or similar rate to unvaccinated (and a whole lot of other assumptions), it almost seems like there is a scenario where the vaccine could be worse than the virus because we're essentially creating many Typhoid Marys that continue to host and spread the virus unaware that they're contagious, giving the virus a massive pool to mutate within.
If vaccinated people do become infected at the same or similar rate to unvaccinated (and a whole lot of other assumptions), it almost seems like there is a scenario where the vaccine could be worse than the virus because we're essentially creating many Typhoid Marys that continue to host and spread the virus unaware that they're contagious, giving the virus a massive pool to mutate within.