Israel is such a small country that the percentage of population killed in these attacks is greater than the percentage of the US population killed in 9/11. Everyone knows someone who was killed, kidnapped or injured.
So yeah, 9/11 has some accuracy as a metaphor.
Proportionally, when the death toll was at 700, that was already EIGHT TIMES the percentage of population as 9/11. In US terms, the equivalent would be 25,000 deaths through terrorism in a single day. (Source: The News Agents podcast)
Six hours ago the death toll was reported as over 1000 in Israel.