UNRWA though is what enables them to do so. If a state has 1m refugees on your soil that don't have any support mechanisms, it's this state's big problem and they'd be soon forced to find some solutions, as it routinely happened with other refugees. To be clear, not all of these solutions are very good, but at least there would be a pressure on the host country to find one. With UNRWA, it is taking care of the "refugees" - who aren't actual refugees for 2 generations already, btw - so no pressure on somebody else to do anything. In fact, it's an established policy - when one of the prominent Hamas leaders was asked, why don't you work to take care of Gaza population, he answered - it's not my business, my business is to fight Israel (he didn't use the word, of course), and UNRWA business is to take care and feed people. Without UNRWA, this wouldn't be possible - no people would tolerate a government that doesn't bother to provide even minimal care to them. But UNRWA provides this safety net that enables the perpetuation of that situation. Hamas can be 100% full time terrorists, because they know the population wouldn't revolt - they have UNRWA to supply their basic needs.
> It's not the UNRWA that is trying to perpetuate itself. It is the actions of several countries that force the continued status of refugee on the Palestinians
UNRWA certainly isn't doing anything to stop it or voice any objection at all to it, as far as I know. They never asked or acted in any way to make anybody except them to step up.
> Israel not providing humanitarian services in Gaza
Israel provided a ton of humanitarian services to Gaza. Of course that was before people from Gaza murdered over 1300 of people from Israel and kidnapped over another 200. Then the idea kinda lost its attraction for a bit. One of the most cruel parts here that many of those who were murdered were of the most active participants in providing those services, and in fact for many of them that was exactly the reason they went to live so close to Gaza - because they wanted to help.