The U.N. Relief and Works Agency for Palestinian refugees (UNRWA) estimates that the city’s population has grown to at least 1.4 million, more than five times its prewar count, with thousands of people sleeping in tents with little protection.
That’s nearly 3/4ths of the whole population of the Gaza Strip at this point.
Rafah is pretty much the last place for people to go, that’s why 3/4ths of the population is there at this point. There aren’t any “safe zones”.