Why’s it become common to say Judaism is a religion but not a race?

How you doing fellow Jews? So I’ve noticed a trend lately, particularly among anti-Semites, to claim that Judaism is a religion but not a race/ethnicity…

I’m not sure how it serves their narratives and wondering if anyone has the answer. I get that in the Israeli case this could be used to say “the Jews don’t need a place of their own because they’re not a “people”” (As if religious tolerance is a guaranteed thing in the Middle east in the first place…), But for Jews as a whole?

I guess this bothers me because I can’t see how a person can hold such an obviously false belief- Jews weren’t massacred in the Holocaust because the Nazis wanted their religion gone…