Yes. It takes a long time to generate the flu vaccine. The strains need to be selected long before the season starts so it's a bit of guess work. That's why effectiveness varies from year to year. mRNA vaccines can be produced in high volumes much faster than traditional vaccines. It would allow the flu vaccine strains to be selected at a better time.
Why the /s? I don't think there is a sure way to estimate what the number of total symptomatic infections would be if there weren't any vaccines, but the fact that unvaccinated are overrepresented in case statistics indicate that the vaccines are working as expected.
