The UNRWA is an organization that is dedicated to perpetuating the misery of Palestinian Arab refugees and their descendants forever. It does not act to resettle them, as the UNHCR does; it creates its own definition of "refugee" that is at odds with the definition of refugee for everyone else besides non-Jews who happened to live in Palestine in 1946-48, and it works hard to ensure that many Palestinian Arabs remain in camps rather than integrate into the countries in which they had been born.
A tiny number of Palestinian Arabs do end up under the aegis of the UNHCR rather than UNRWA, notably those who were kicked out of Iraq. Slovakia just agreed to accept nearly a hundred of them temporarily while permanent homes are found elsewhere. Arab nations, of course, have no interest in resettling them - although hundreds of thousands of Iraqi refugees did flee to Jordan and Syria, the ones whose ancestors lived in Palestine are not accepted.
The UNHCR, which is the UN organization that is responsible for every real refugee on the planet, just announced that because of a budget shortfall they wil not be able to extend medical care to some 600 Iraqi families in Jordan.
What are the budgets for the two refugee agencies, the one for Palestinian Arabs and the one for everyone else? As far as I can tell, the annual UNHCR budget is between $1 billion and $1.5 billion, and the annual UNRWA budget is about a half-billion dollars (possibly higher this year with extra appeals.)
However, the UNHCR is responsible for nearly 33 million people. UNRWA says that 4.6 million "refugees" fit under their definition but in fact there are less than two million registered "refugees" that take advantage of their services.
Which means that UNHCR's spends something less than $45 per refugee, while the UNRWA spends over five times that amount per fake Palestinian Arab "refugee."
If the world really cares about Palestinian Arab refugees, a number of tasks are way past due:
Discard the definition of "refugee" that guides UNRWA, immediately reducing the number of Palestinian Arab refugees from millions to the relatively few who were displaced in 1948.
Shame Arab countries into stopping their enforced discrimination against Arabs of Palestinian origin and start naturalizing the millions of Arabs who were born in their countries.
Dismantle UNRWA altogether, and place the few remaining real Palestinian Arab refugees under the umbrella of UNHCR where they can be resettled.
Take the bloated UNRWA budget, which now runs schools, medical clinics and other wonderful services that the real refugees of the planet cannot take advantage of, and re-allocate it to people who really need it.
The only reason this has not happened, and the only reason the number of "refugees" keeps increasing over six decades after the war that displaced them, is because of a lie - the idea that this is necessary to maintain Palestinian Arab "unity." If they are naturally unified, they don't need their brethren to oppress them to maintain that unity; if they aren't so unified then the entire idea of Palestinian Arab nationalism is a lie that is artificially maintained to pressure Israel.
The only way to find out would be to stop the endemic discrimination against Palestinian Arabs in the Arab world, allow them to become normal citizens - and see how many take advantage of that offer. In Lebanon, a number of loopholes have popped open through the years that tens of thousands of Palestinian Arabs took advantage of to become citizens, and then those loopholes were shut tight. Imagine how many would jump at the opportunity to become Arab citizens if they could?