A life saving blood transfusion or avoid forever chemicals likely already in my body, hmmm what to choose...
But does it have to be one or the other? Or is there some possibility of somehow removing the PFAS from donated blood?
What makes PFAS so difficult to deal with is the fact that they are particularly inert. Teflon works because it doesn't react with almost anything. I've seen some studies about using UV light to kill off PFAS, but that's not going to be desirable when you want those red blood cells to also survive.
I think people getting blood usually have lost a bunch of their own first. And blood isn't usually given just for fun, it's to save their lives, i.e. PFAS isn't a huge concern at that point.