I agree that anti Zionist has become a popularised term and is also being used as a proxy for antisemitism, but I also think there's a lot of people who call themselves anti Zionist when they're actually what they're specifically against is neo-Zionism (i.e the expansion of Israel into wider territories).
However, I do also understand why Israel felt the need to expand its borders in order to strengthen its position and protect its people. The UN and the UK let Jews down horribly with their original plan for Israel and it was implemented awfully - the original map left Israeli Jews geographically vulnerable due to there being narrow chokepoints and areas of potential disconnection, meanwhile the British had historically drawn up at least 3 conflicting agreements promising the land to various groups including the Palestinians and Jews which led to a natural conflict in terms of who had the right to live on the land. Palestinians were displaced, often with no compensation or restitution, breeding resentment. Neighbouring Arab countries refused to recognise Israel's right to exist as a Jewish state and were openly hostile against it, so I also recognise there was an existential threat to Jewish people living in the region (many of whom were also exiled from their homes in Arab states).
My personal position is that I agree that the only way to protect Jews and Jewish interests in the longterm was to have a Jewish state, and that Jews were badly let down in the implementation stage of that state being built. I understand why Israel felt its borders needed to move, I also understand why this was met by resistance. It's been a cycle of trauma and violence from both sides. To then use this historical Israeli backdrop to terrorise and attack people on the basis of being Jewish is abhorrent and textbook antisemitism, the Palestine situation has been a convenient tool for antisemites to try and hide behind.
That's not to say that there isn't also a justification for criticising the Israeli government's actions in recent years and openly campaigning against needless cruelty on Palestinian civilians.
I think it's good to interrogate what people mean when they say they are anti zionist and invite introspection on why they hold such strong opinions, I've found this thread interesting - whilst most of my childhood friends were Jewish and I have many Jewish friends still, it's been almost a quiet rule to not mention Israel/Iran or go into deeper discussions around religion/our cultural backgrounds so it's been good to see a more unfiltered British Jewish perspective. Thank you to those who have engaged in good faith