Israel isn’t “bombing stuff into oblivion”, they’re doing two things:
Attacking subterranean structures with ground-penetrating (aka “2000 pound”) bombs, and
Clearing a one-mile cordon along the border of structures so that Hamas attackers can’t do what they did on Oct 8, which was train and amass along the border fence in secret, hidden among the buildings and blended in with the populace.
If your army has to cross a mile of open ground to attack your fence, it’s a lot more obvious when they start. One of the reasons they succeeded in “surprising” Israel is that they just were there right by the fence, for years, until it seemed “normal.” With the buildings gone, they can’t do that.