The real answer is 19th century warfare in the tunnels where all of Israel's tactical advantages disappeared.
But instead they cowardly ordered 2,000 lb bombs that didn't accomplish any of their stated goals and killed their own hostages. Instead they designated everyone in Gaza as a terrorist and killed their own hostages when they managed to escape because everyone has the same Semitic phenotypes (awwwwkwaaaard). Instead they put their freshman IDF conscripts on social media to claim any dissent of the military strategy was incitement against Jewish people's right to exist. On the social media front, I'm not sure what's more embarrassing, getting paid to do that, or not getting paid to do that.