Gaza was controlled by Egypt for quite a while. Israel occupied it and the Sinai after the 1967 six day day war. When they returned the Sinai to Egypt they also offered Gaza back as well so it could go back under their control, but Egypt refused as they didn’t want to take on all the Palestinian people who could potentially destabilize Egypt.
Jordan also wouldn’t want the west bank back (not that they really have a claim to it either) because Palestinians in Jordan tried to overthrow the monarchy there.
Now that there’s a Palestinian identity (instead of just a general Arab identity like it used to be) the Palestinians need to have their own self governance and independence. Absorbing the territories and population into other countries isn’t going to be a solution.
Both sides need to cut out the bullshit and negotiate in good faith to find a long term solution. Unfortunately with how entrenched the hate is it’s sadly unlikely to happen. The cycle will continue until both sides want it to stop.