The role of the UN is largely performative. It exists as much to rally various countries to independent action as to create global consensus.

So the Israelis show up in striped pajamas and grease paint on their faces, while insisting that every living Gaza resident is another Tomás de Torquemada, and a bunch of American press agents film them in sepia while playing violin music. And then Congress green lights $14B in anti-Palestinian nerve gas while the sea otters on cable news clap.

Loudly yelling at the UN gives them a platform to demonstrate how strong and resolute they are in the face of all the anti-semites in the world who want to kill them because they're Jews doing Jewish stuff. It's political theater for their supporters at home.