You have obviously never served in the military, certainly in a combat role (as I have). This is why it seems strange to you.
Depth is a fundamental requirement for any defence. This is a basic principle of warfare.
The IDF tried to do the impossible (using technology & firepower as a substitute for depth) and on Oct 7 it blew up in their faces.
Depth is essential because ANY position (observation or firepower) or armed force that is located on a fixed line (border) can be attacked and destroyed by an attacking force in a surprise attack.
ONLY by having obstacles to movement behind that fixed line and hidden firing points in depth behind that fixed line can defending forces have the time and space to organise defensive forces at the points of concentrated attacking forces.
To attack you must concentrate your forces but the attacker has the advantage of choosing where to concentrate and break through. Depth gives defenders the time and space to organise.
Without it you get what happened on Oct 7 when the enemy breaks through to rear areas and causes havoc.
The IDF is the best army in the world, but is still subject to the basic, timeless realities of warfare.
No, I havn't served in the military but I get your point. That being said, when I heard about the Hamas blowing up the fences and invading, I thought it was a bit strange. So I talked with a couple of my friends(former IDF guys), who told me it was not "a bit" strange but "really" strange, because that border is one of the most strictly guarded in the world. They suspected the border was left effectively unguarded somehow for who knows what. Considering IDF's firepower and training, Hamas didn't try this kind of reckless ground operation in the past because they knew the risk was too high. Launching rockets from a distance was more sensible for them. Maybe there is more than meets the eye, and I wonder who benefits the most from this war, politically or economically or both.
I served in the Australian Army Reserves. Australian soldiers are called "Diggers" because digging trenches and fortifications is so basic.
I think the IDF relies too much on technology some times.
Tech is great but you have to remember the basics.