See post 15.
“Egypt is guarding the Gaza border permitting none to leave and carefully controlling what is being allowed to enter.”
Post 15 explains why they won’t let them leave.
The fact Israel has made it quite clear they will destroy anything coming in, and those that bring it in, is why nothing is being allowed in by Egypt. Egypt does not want open war with Israel... don’t get me wrong, if somehow Iran nuked Israel there is little doubt a decent segment of the Egyptian population would be dancing in the streets, but the government knows full well they have no chance militarily against Israel, and know full well, Israel will make good on its threats.
Egypt is a party to the Abrams accords that is a coalition of Arabs that matter and Israel against Iran