This is just hyperbole. Plenty of people on the left have called out antisemitism. I would agree that there is an extremist segment on the left that isn't exactly helping its own image with regards to antisemitism. But I wouldn't frame it as "the left".
While I agree with the point that it is not the wider left, as in the voters, I consider myself to be left even though some consider me racist for not respecting hate beliefs that come from religious dogma, it is undeniable that these extreme manifestations of what I call "the vocal/ internet/ college kids" left is left unchallenged by the majority. If we are going to call out the right for not doing enough to distance themselves from the far right, then the same is true for the left.
I am not actually that much in to politics and I find the tribalism to be absurd. My desire is that the Western World does not decent back to fascism,extreme racism and that all that was built over the decades goes to s. The left as a political entity, be it in the US or UK, instead of pushing aside the extreme manifestations and often times racist (against white people) and anti-Semitic and sexist even, by the media they control, they embraced these things. All this does is to push more and more people not just to the right but to the far right.
Do we really need to get to a fascist US and again to a fascist dominated Europe before the left decides that pandering to extreme versions, that having mutually opposing views in a schizophrenia like manner, was not the best of ideas? Do we need nazism to come back before we can admit that pandering to everything, no matter how abhorrent but acceptable because of "magic" was never going to create a better World but a more violent and hateful one?
The left for a long time was 10/10 with dealing with the Christian hate beliefs and the anti science that resulted from that. Today? Religious beliefs are a shield against any and all things. This is just one side of things, there are many others, like Biology teachers being abused because science does not conform to gender ideology, physics, archeology and even democracy itself have become "sensitive" subject because they might upset some feelings.
I said it before, if the Western World goes to s, it will not be because the far right found a magic pill or an extremely charismatic leader (Trump is disgusting even by many of his voters standards, from my experience) but because the left is disintegrating.