That is not straightforward at all.

Israel is founded on two notions that the world has largely rejected in modern times: first, that a land can be for a particular ethnic group, to the exclusion of others; and second, more strongly rejected, that force is an acceptable way to obtain the land for that group.

Although neither of these were considered particularly controversial in the past (c.f. colonialism), Israel had the distinct misfortune to be last to the party.

When you use force to institute a modern ethnostate, you can absolutely expect an opposition movement that has nothing to do with prejudice against the ethnicity, but everything to do with rejection of force to establish ethnostates.

(Yes, I know Jewishness is more complex than an ethnicity. It's close enough for these purposes, however, given that those who hate Jews will maintain their hatred against even Jews who do not claim their Jewish identity--so in this way, it functions as an ethnicity, which you cannot disavow, more than as, say, a religion, which you can.)

However, anyone who is prejudiced against the ethnicity is likely to join in the movement as it is an excellent cover for their prejudice, resulting in a complex mixture of prejudicial hatred and non-prejudicial aversion to violence and oppression. And when the most natural location for a homeland for a people is where pre-existing and neighboring countries largely reject liberal democracy, it gets more complex yet, as approaches that are not backed quite intimately with force tend not to carry much weight.

This is the fundamental complexity of the issue.

To pretend that it is simple, or that antisemitism and anti-Zionism are the same, is either deluded or disingenuous.

This is not to say that the complexity cannot be navigated. You provide some arguments to start picking one's way through the complexity (e.g. given the prevalence of antisemitism, having a Jewish state, i.e. supporting Zionism, has a particular moral justification that is lacking in most other cases). You also correctly point out the hypocrisy in degree of attention (but this might only mean that other conflicts deserve far more attention).

Nonetheless, the existence of potentially compelling arguments in a complex situation does not mean that the situation is not complex.