I don’t think the lighter connects to the computer. It’s like a controlled short circuit and has a dedicated breaker and direct connection to the battery/electrical system.
The main problem with a contacts is a heat built. The current drawn by the camera is pretty low, the continuous use shouldn’t cause any significant heat build up even if the contacts are not in a perfect shape. In case of more power hungry device the quality of insert and condition of the contacts are in question for the continuous use.
It has nothing to do with a car’s computer.
I had a cheapo Garmin GPS plugged in to my previous two cars for years. Nada wen ti.
It’s an old wives’ tale that has some basis in fact. The power coming out of the lighter socket is unregulated, which means (in a vehicle) that it can be all over the place. Various high-current loads switching on and off can cause big voltage spikes.
However as long as you are using a cable designed for the job (ie., something with a lighter plug on one end and a USB plug on the other) it will be internally protected against such things, and the USB output will be regulated. None of the electrical crap that appears at the lighter socket will make it to the USB end, although YMMV. A made-in-China cable that cost NT$99 at the everything shop might not be the best choice.