Why?
One reason is because the covid virus itself is a positive-sense RNA virus. It’s mRNA.
So unless you manage to also avoid the virus you’re still getting the mRNA that the Pfizer and Moderna vaccines use, only you’re getting the entire virus genome at full strength instead of just the spike protein alone.
mRNA are instruction sets telling cells to create proteins. Your body is processing mRNA every time it makes a protein, which it is doing a billion times unless you are dead. People posting these ridiculous threads don’t know basic cell biology and they eagerly share their ignorance with the rest of us.