Many peoples have suffered wars throughout history, were displaced and relocated in other countries. Only the palestinians retain their refugee status even after living in surrounding arab countries like Lebanon, Syria for more than 3 generations.
There are more than 2 million arabs that remained in Israel and didn't flee during the 1948 wars, they are all full citizens now, in full contrast.
The only reason for keeping palestinians in a refugee status is to keep the conflict going until the eradication of the state of Israel.
UNRWA is a known cover for laundrying Hamas activities, there are many accounts of Hamas members firing and conducting military activities wearing UNRWA uniforms and traveling in UNRWA vehicles. That's why many countries stopped supporting them financially