If it doesn't harm, perhaps it's worth still participating in something for the collective good. I know you Americans don't often reason that way.
That said, one could question whether vaccinating healthy people will indeed lower the transmission speed qnd thus be q collective good.
But I often hear people just considering what's good for them as individuals as if that was all what matters
EDIT: just to make clear, I'm not advocating for compulsory vaccinating people who don't want to; just trying to offer a different POV so people can choose to behave in a selfish way while fully understanding that they are indeed acting in a selfish way, benefiting from a functioning society and choosing to not give back even if it doesn't cost much