There is a sense among many that the overall vibe has changed. I can buy that---the nativist and anti-globalist vibe in America, and on this message board, has changed, and Jews may well become the totems for that, as they often have. But numbers are harder to come by. The ADL, which does much of the counting, has been open about the fact that it considers Jewish anti-zionist groups like JVP to be hate groups, and their demonstrations (made up largely of Jews) to be anti-semitic acts.[1]
My point is just that if we're talking about vibes and sense of the discourse, there are many Jews (myself included) who also are deeply suspicious that, as the parent said, "everyone who is Jewish constantly fears for their life and lives with daily radical antisemitism." You asked why they find it hard to believe. As an n of 1, closely connected to an n of many more, I find it impossible to believe.
[1] https://twitter.com/JGreenblattADL/status/171479177486948797...