Why SA came to Yemen to start with?
I see you are an anti Saudi bigot and ignorant too boot.
The Houthis regularly attach Saudi Arabia with missiles and drones. They are at war
The border between SA and Yemen has been contentious for a very long time. Traditionally SA raided the Yemen border towns for slaves. On the Saudi side there is tremendous wealth. On the Yemeni side they don’t have enough water grow crops to feed their own people. This situation would be like Haiti attacking the US, hopeless, unless they had a rich and motivated patron.