Palestinian Resettlement or Inherited Refugee Status?

I have never understood why being a Palestinian refugee is an inheritable condition.  I thought refugees were supposed to find some place to live permanently after being displaced from their former country.  It has been almost 70 years since the original refugees left Israel on the advice of the Mufti of Jerusalem, among others.  The vast majority of Palestinian refugees have never seen the places that they are refugees from.  They are still supported as refugees by a unique UN agency, United Nations Relief and Works Agency for Palestine Refugees in the Near East, which guarantees the descendants of the original 1948 Palestinian refugees welfare payments, free healthcare and education  from the UN forever.  The UN makes no effort to resettle these people anywhere else.  There were 700,000 Palestinian refugees in 1948, and now there are 5 million.  I don't see how essentially locking these people up in Palestine for a cage match with the Israelis helps them. They should be offered resettlement.