Most of the food that has been coming in to Gaza has been brought in through the tunnels, so it's not at all correct to say that they've only been bringing in weapons. But almost a million and a half people need a tremendous amount of food every day (far, far more food is needed than the amount of weapons that Hamas has been bringing in), so it simply is not possible for them to smuggle enough food in through the tunnels to feed their people. And of course, the Israeli military has destroyed most of the tunnels, so now there is no way for them to bring food in (further evidence of genocide).

And of course, they have to rely on handouts, since they are not able to buy necessities with money they have been able to earn through their own economy (because the government of Israel has destroyed their economy), and this also poses limits on their ability to provide food for their people.