It's 0.5% deaths only in perfect conditions, which go out of the window without measures which very few countries are able to enforce.
And you also have to account for people with permanent damage who didn't die, and for the economic and social effects of lockdowns even if a single country manages to keep this under control, because not everyone else will.
And you don't have to push the vaccine to everyone, it's also useful if you just deploy it where it's more likely to be necessary.
"Across 51 locations, the median COVID-19 infection fatality rate was 0.27% (corrected 0.23%). ... In people < 70 years, infection fatality rates ranged from 0.00% to 0.31% with crude and corrected medians of 0.05%."