The numbers are provided by Hamas so it's not reliable.
They families share a responsibility for the death of the children because of their refusal to move south.
People who have moved are not burying their young children. So it is safe there until the war is over.
The type of ordinance used by Israel to date is designed to minimise civilian casualties - the bombs detonate upwards instead of sideways. See the type used by Russia in Ukraine for comparison.
In wars, people unfortunately lose their homes and sometimes, their lives. It happened in Libya, Syria, Iraq, Chechnia, etc. If you want to blame anyone, you should blame the party that started the war. Not the one retaliating for the attrocities committed against their citizens.