Surely you realize that this is completely unhinged?
You are apparently an intelligent person. Doesn't it strike you that there should be a moral dimension to this? That there is a right way to act that is independent of realpolitik? Do you not realize that those people are, quite literally, under the care of Israel's government, and that to "cleanse" them would be a crime of world-historical proportions -- even if it might make life a little bit easier for people in Tel Aviv?
Besides, I don't think you understand what the reaction would be. Also, I think you overstate China's willingness, and Russia's capacity, to meaningfully support Israel should the US wash its hands of the region.
I'm not endorsing the ethnic cleansing of Palestinians if that's what you mean. At the same time, you can say that Israel has lost peoples' hearts, that it goes against international law, that it's unhinged etc etc but none of those things will stop the people in power in Israel, who btw are textbook fascists who spit "peace" like a dirty word, from doing whatever they like.
Historically speaking, the Holocaust did not end until the Allies invaded Germany (and even then, it continued until the last moment) and the massacre of Palestinians will not stop until a large international force invades Israel. This will not happen, so the massacre will continue until the last Palestinian dies or leaves and Israel extends from the river to the sea, just like the settlers want it.
That's the facts on the ground. In Lord of the Rings, the bad guys lose. In the real world, they often get their cake and eat it. You can call it unhinged, or realpolitik, you can insult me and attack me, but you're just shooting the messenger.
My impression yet is that unless something radically changes, I don’t think Israel would lose US, the power vacuum in the region would be filled by somebody else, something US is unlikely to allow. Despite the show, I don’t believe Biden/Netanyahu’s fallout; it’s simply the only way Biden can do at least the tiny amount of damage control that allows him to keep the most of Jewish/leftist voting blocks.
The other thing to keep in mind is that Israel is a nuclear power and there are no others in the region (for now), so that, too, gives them some extra time and leverage.
I totally agree that all this is just hypothetical and I, too, am not convinced that Biden is going to take serious action on Netanyahu. I would think that he's royally pissed off at him, privately, though. Bibi has caused Biden no end of trouble and I think it's clear that if Biden lost the elections, Bibi would celebrate.
Israel has a fully mechanised army, tanks, F16s, drones, rockets, bombs, nukes, while Hamas has ... their grandpas' hand-me down AK-47s? What are they gonna do to genocide the Israelis? Give them the evil eye?
But even if that were not the case 20 years is plenty of time to cleanse Gaza, and the West Bank with it, of every last Palestinian. I'd say at the current rate it would take hardly a couple years.
Edit: to be fair, I don't know how to compare SA and Israel. Maybe you have a point, but I don't think it's that simple to impose any kind of, essentially, sanctions to Israel as long as Uncle Sam's got its back. That special relation is a pretty big trump card there. And, btw, we're still at a Democratic president. Can you imagine the Republicans letting Israel suffer arms bans and trade embargoes?