To be fair, infections after the vaccine are so mild that few people notice them, thus will not isolate. And the effectiveness at preventing transmission drops

To be fair, infections after the vaccine are so mild that few people notice them, thus will not isolate. And the effectiveness at preventing transmission drops by something like 10% every month after the vaccination. Maybe this is due to delta-variant increasing? And after delta, there will be epsilon ... and so on. Whatever strains escape the immunity created by the vaccines will be what spread. De facto, vaccinations will not stop the spread and will not stop mutations. But they do prevent serious disease and death.