That's not true - Palestinians are allowed to evacuate. The border has been closed by Egypt, not by Israel. Just this month, for example, a group of children was evacuated and flown to the UK for urgent treatment. Since Gaza has no airport, they could only leave through Egypt or Israel.
For context, there was an Israeli volunteer organization called Road to Recovery, made up of citizens who drove patients/children, the elderly, and others—from the border crossings to hospitals across Israel for medical care. Many of the volunteers lived near Gaza themselves. On October 7th, when Hamas invaded Israel, those very volunteers were deliberately targeted and murdered. One of them was Vivian Silver, a remarkable woman who dedicated years to this mission.
The cruelty, hatred, and fanaticism of Hamas is almost impossible to grasp for those who don’t live with it. It’s easy to get swept up in narratives shaped by popular media, but those accounts are rarely impartial when it comes to this conflict.