It could have a myriad causes. On the video is over bluetooth, so a noisy radio environment, or some weird glitch on the bluetooth controller. If it happens on

It could have a myriad causes. On the video is over bluetooth, so a noisy radio environment, or some weird glitch on the bluetooth controller. If it happens on the trackpad, it could be a defect on the trackpad itself, or something overloading the USB hub it's attached to. It could also be a sign of swapping, too many interrupts, badly prioritized processes, etc. A bug in adaptive refresh rate might do it. A process messing with events (such as an app listening on mouse moves or an antivirus). It may not be a single bug, but just a symptom of something else.