Literally go watch the videos of journalists in the tunnels. Nothing will change your mind.
https://www.ynetnews.com/magazine/article/b1xzpxbnt history of the tunnels
https://en.m.wikipedia.org/wiki/Palestinian_tunnel_warfare_in_the_Gaza_Strip
https://youtu.be/E7SwJtYW86U?si=TbxPd_CGqO4ahpp0
Literally go watch the footage.
https://youtu.be/W4gDfSNMRx4?si=vVvN7609vuYHRkuu
It's easy and cheap using smuggled concrete not doable in days with functional air conditioning systems.
https://youtu.be/a_n8qj8ycok?si=4uWZsaddS5KQGRxX
https://youtu.be/WUBxjB2NFMU?si=CGNkZJ0zwEDnZZh_
It takes time to disarm a possibly booby trapped tunnel and avoid potentially collapsing the buildings with civilians on top. It takes time to do an investigation of a crime scene.
It's been geolocated. Try again.