These things don't exclude each other. Also, people can be more expensive and less reliable than machinery.

Moles can testify. Cameras cannot.

Technology doesn't have family members you can cripple.

Exactly, where there's a will, there's a way.

What is your interpretation of a will?

Automation thru better tech infrastructure is key. Moles keep asking for more benefits, like insurance, improved health coverage, increasing travel expense and so on. Money is not raining on anyone including gangs where any service price can be paid, no question asked.

That always carries the risk of leaving a trail somewhere or getting set up by a sting operation. Tech, assuming it's reasonably well secured (and tamper proof is ever easier and easier to achieve), doesn't.