Because Israel is committing genocide, Apartheid and a whole new, Israel-brand crime against humanity. Usually you don't need to pass this many resolutions against a single problem. Israel's brutal occupation and genocide of Palestine has the whole world's eyes, so they get more international attention. Not to mention it's been going on for 74 years. If you start counting from 1945 when the UN was made, that's the world's longest-lasting series of crimes against humanity and it's not close.
Also even if you disregard the UN, many reputable human rights organizations have condemned Israel for war crimes and crimes against humanity for ages. If you think all those are biased against poor old Israel, then you should check your biases.
The Gaza Health Ministry's numbers are trusted by the whole world, including organizations like UNICEF.