After seeing Garmin GPS units duct taped in Russian cockpits and cannon cameras in drones we can probably exclude Russia. China is still incapable of building

After seeing Garmin GPS units duct taped in Russian cockpits and cannon cameras in drones we can probably exclude Russia. China is still incapable of building complex home grown avionics and more importantly propulsive systems. When you are still reliant on licensing jet engines you probably aren’t flying nearly physics breaking aircraft. EW is a possibility however sensor spoofing still requires an asset near by and one with a lot of on board power. Many of those incidents weren’t where Russia or China could realistically deploy assets too. Right now the most plausible scenario (other than sensor artifacts and delusions) is that it’s either the US themselves doing it in secret or the private sector they are the only ones with the means to really test systems like the ones observed so far.