Well, no.
"Wired alarm sensors are inherently more reliable than wireless alarm sensors" is a statement than is 100% true, but it requires a lot of caveats.
Here in 2018, most of the factors that affect wireless alarm sensor reliability has been mitigated (but not entirely eliminated) by most, though not all, alarm equipment manufacturers.
Question: what potential problems can affect wireless sensors?
Answer: wireless sensors can be jammed, spoofed, lose signal due to environmental factors, or run out of battery.
As I said, the modern wireless sensors have mostly mitigated these issues, because somebody will absolutely sue the pants off you if you continue to use hackable wireless sensors with known vulnerabilities. So most sensors have jam prevention and spoof prevention capabilities, although of course some are better than others. Modern sensors send a supervisory signal and a battery level signal back to the panel, so that you know that the sensor is still alive and has a reasonable amount of power. Most sensors have built in tampers, in case the bad guys get an attack of the clevers and try and bypass the sensor at the transmitter.
But these only mitigate the problems inherent in wirelessly transmitting a complex signal, they don't erase it. It is very possible that a dedicated program carried out by someone with enough time and resources- a state actor, for example- can figure out a way to jam or spoof a wireless sensor, and then what? If a clever person figured out how to stand outside a protected area and zorch the alarm inside the protected area, it's game over, you're now only protected by your locks.
Not to mention the fact that these countermeasures use power, and thus have a non trivial affect on the lifespan of the battery.
Many of the inherent problems of wireless alarm sensor technology, even the now-mitigated ones, simply aren't present when using wired sensors. An attacker, even a very clever and well equipped one, has a much harder time attacking and disabling the sensor simply because they can't intercept the signal from outside the protected area. An insider can attack either the wire or the sensor while the alarm is disarmed but 1) that's a lot trickier, you need access to the wire or the sensor, and 2) that risk it mitigated by supervision.
So, let's talk about the Interceptor.
Some devices in an alarm system are going to be wired into the communication bus or the auxiliary power output of the alarm panel. Examples include powered sensors like smoke detectors or motion detectors, which are powered by auxiliary output power, or peripheral devices like keypads or wireless receivers, which are powered by the communication bus. There is a risk that the power going to a sensor or a peripheral can be shorted, and, if the panel doesn't have power line protection, this can cause the panel to lock up.
Of course, this problem only exists with certain panels. It's not a problem inherent to wired alarm circuits, per se.
Bottom line: wired sensors are technically more secure than wireless sensors, but most wireless sensors on the market today are pretty darn secure. The average integrator probably won't see much of a difference in the security or reliability either way.
