The u.s.a. was already condemned in the case of Nicaragua and nothing changed and nobody knows that, in the very improbable offchance that Israel was condemned, they would just act like Russia when the International Court of Justice ordered them to leave Ukraine.
Let's say that our medias talk about this improbable success and, even more improbable, support the ICJ and condemn Israel, everyone would just forget a month later. Sure, there's nothing to lose by trying, but not much to gain either, it's not the beginning of an effective solution, it'll be the exact same shit as before.
And the ICJ wouldn't even need to be considered the bad guy, the contradiction wouldn't raise an eyebrow, but let's say i'm wrong, have an hope in this if you want.

edit : That's an exaggeration, those who hate Israel won't forget such judgment and would remind us when they got the chance, that's the difference i'm seeing, so you're right to say that it's not nothing to be able to label them officially as genocidal, it'd add a new argument/insult of choice.

That's ~two every three years :