Legal isn’t the same as moral, but there is no consensus on the morality of war. Some people are pacifists and believe all war is immoral. Most people believe war is justified if it has a legitimate casus belli.
Whether or not Israel is committing genocide is a separate question from whether a military action is morally permissible, because genocide involves actions with no military purpose. In other words it’s possible that strikes like these are morally permissible even if a government is also doing things that are illegal, like blocking aid delivery.