This is the issue with discussions like this. Arguments about any medical intervention is always about statistics, there are essentially no 100% measures, but you and others always frame this as either or questions that's either completely naive or dishonest. So yes vaccination was also stopping the spread, but nobody thought it would 100% prevent a vaccinated person from getting infected. However it does significantly reduce infection rates and severity of the illness. The hope/assumption was that if sufficient people get vaccinated and the infection rate for vaccinated people drops enough it will stop spreading of covid. AFAIK It's unclear yet if that we haven't stopped the spread is due to insufficient vaccination rates or insufficient drop of infection rates for vaccinated people. This analysis is further complicated by the advent of new variants like omikron.