Because Judaism is simultaneously an ethnicity, a race, and a culture, and a religion, they have avoided assimilation into the larger cultures in the places they have lived. This causes resentment between the cultures. Look at how so many people view immigrants today. Now stretch that attitude out over 2000 years. With Jews always being in the minority, they become an easy target for hatred and scapegoating. They’re very obviously culturally different from other people where they live, by choice, so they’re an easy target for that kind of xenophobic propaganda.
Some of the negative associations were earned, like the “Jews and money” stereotypes. That comes from a long time ago when all abrahamic religions followed the moral code that charging interest on loaned money was immoral. The Jews believed this too, but because they are God’s chosen people and everyone else is not, they decided there was no moral problem with charging non-Jews interest. They would give out loans a lot more aggressively because there was a profit motive and risky loans could still be profitable. They became associated with money because they proliferated as bankers due to what was considered at the time to be unscrupulous banking.
None of that background justifies any modern antisemitism; hate is always wrong. Just answering where some of it came from historically.