Earlier quoted context omitted.
The problem is that vaccination protects you from having a bad case of Covid, but it doesn't protect you from getting infected and infecting others. So, if the vaccinated carry on as if it's 2019, the disease will jump from one vaccinated person to the next until it finds an unvaccinated person.
> vaccination ... doesn't protect you from getting infected and infecting others Thankfully, this is wrong on both counts. 1) Vaccinated people are significantly less likely to contract the virus 2) Breakthrough infections are significantly less contagious than infections in nonimmune persons There's a good article diving into this at https://www.washingtonpost.com/politics/2021/11/22/most-pern...
Recently vaccinated people are significantly less likely to contract covid than totally naive folks. Efficacy against infection seems to wane pretty heavily over time.
> Breakthrough infections are significantly less contagious than infections in nonimmune persons
This seems to be in dispute (by a study referenced in your linked article). I think it would be fair to say they are at least contagious for a shorter duration though.