COVID-19 IFR seems to be more like 1% (compared to an IFR of 0.05% for polio, for example) but more infected will suffer from damage to respiratory tissues and other complications.

MMR vaccines are mandatory for school children so, if you've attended school in the US, odds are you've been vaccinated against mumps, measles, and rubella.

Polio has been wiped out by a massive vaccination campaign. It's no longer a threat precisely because of vaccinations.

Meanwhile, the COVID-19 vaccines greatly reduce the chance and period of transmissibility, reduce disease severity in breakthrough infections, and only require boosters for those populations whose immunity wanes. The latter also applies to those infected with COVID-19. Reinfection can and does happen. Vaccines can help counteract that.

The biggest benefit to vaccines is not just personal protection but also how much they work to limit spread. This is crucial in stopping the pandemic because the longer and easier COVID-19 is allowed to spread, the more likely it can mutate into a strain that's more virulent and harder to fight. We saw this with Delta.

Here's a helpful video by potholer54 explaining the difference between the two - https://www.youtube.com/watch?v=eAB43K2gtOk