Vehicle tracking companies is not effective

Is vehicle tracking companies still relevant and effective to prevent vehicle theft. I believe not. We are clients of Netstar for many years. The contract was not an entry level package. Despite believing that Netstar is an established tracking company my vehicle was ******. The tracking system was "jammed" at the site of the theft. The tracker did not even send a warning on the app. Is vehicle tracking companies still on track or are they losing the battle against ********s. Why do insurance underwriters want clients to install a vehicle tracking device when there is no change to recover the ****** vehicle. The latest is that underwriters want a client to install two tracking devices (with two monthly premiums at two different companies) to comply with insurance policy requirements. Why, if the devices are jammed, thus resulting that the ****** vehicle lost without any way of recovering it.