Current vaccines are non-sterilizing and therefore do not effectively stop the spread/transmission of SARS-CoV-2 (the virus) but is very effective at preventing the disease the virus causes (COVID-19). Initially the vaccines were able to keep viral loads low enough to meaningfully stop the spread, but the Delta variant resulting in far higher viral loads and removed that advantage compared to the original virus.

Arguing that the infection rates are uncorrelated is one thing, but serious illness and death is what we really need to care about with this virus. And for those metrics, vaccination is highly-correlated to better outcomes.

That’s a common error, reused by antivaxxers. They are indeed because even what we consider relatively high infection levels are just enough to get 15-20% of the population infected per year. This is less than the part of unvaccinated people. That’s why having a very high vaccination rate is critical to kill COVID. Above this threshold you’d see the infection rate affected. Still, vaccinations are good strategies because they still reduce infections, or at least severe forms of it. Without it in many countries would have been totally saturated by Delta.