There’s a difference between leveling Gaza (as you said) versus, going into a neighborhood, where the IDF has identified to the Palestinian civilians and told them to move out of that neighborhood for their safety.
The goal here, for the IDF, as said by Prime Minister Benjamin over the last few days is for the IDF to find the tunnels and then to thoroughly destroy them. That’s what they are doing right now in their operation.
It has already been done for all of northern Gaza — they sent leaflets around in northern Gaza and told everyone to get out for their own safety. Northern Gaza is a ghost town right now except for tunnel rats.