Arabs are weak how many countries with wealth, manpower and technology do they have. And they cannot defeat a tiny Jewish state slap in the middle of MENA.
It's not just Arabs that can't intervene to stop whats going on in Gaza. Its a lot of other western nations along with even Turkey because Isreal has the diplomatic cover by the United States and military cover by the United States because it being an ally and a strategic asset to them.
If it wasn't there would be military interventions much less sanctions for what they are doing. There are zero sanctions because those are all administrated and forced through the United States.