is to protect against severe illness and death, and the vaccines we have demonstrate outstanding performance in that regard...
The attached link explains the function(s) of our COVID vaccines in significant detail for those of us who aren't specialists in the field...you might want to pay special attention to the role of "T-Cells", and how they keep those infected from ending up in hospitals, ICUs, or morgues.
It makes zero sense to go unprotected from severe illness or death...so, all intelligent people choose to get vaccinated.
Link: https://www.nature.com/articles/d41586-022-00214-3