1. Image and video files are very large.
If they were being transferred from your drone or tablet, you'd probably notice.
So far despite the hype and hysteria around this topic, I haven't heard anyone reporting any suspicious large data transfer.
Your photos and videos are stored on an SD card - not in the app.
You pull the SD card, copy to your computer and DJI never sees them again.
Even the extremely vague DHS warning didn't suggest that DJI siphons off your images and videos.
That's something the more imaginative users, primed with too much sci-fi and Hollywood but not enough critical thinking have come up with.
The warning from DHS’s Cybersecurity and Infrastructure Security Agency (CISA) only said that: the unmanned aircraft are a “potential risk to an organization’s information” and that the drones “contain components that can compromise your data and share your information on a server accessed beyond the company itself.
There's no hint there that your images are being scoured for strategic value.
And as I mentioned, the idea that drone flyer's images and video are going to provide a rich source of espionage material is simply ridiculous.
To be clear, I am not saying anything specific is happening for sure. However, I am saying that the potential threat is there and that it is naive to just say "no way chicken little".
15+ years ago the company I worked for was requiring an annual "bright ideas" presentation from their employees - kind of a joke, but be that as it may, I proposed that the company actually do a presentation/training session on what employees should do in the event of an active shooter. That was after there had been an uptick in workplace violence and shortly after a news story broke of a disgruntled, estranged husband grabbing his wife's company access badge and walking into her building and shooting up the place. The response from management, to include an individual that was part of the county's EMT team was basically, "um, that's nice, but no." His specific response was that "we don't want to be like chicken little saying that the sky is falling and throwing people into a panic." I moved on to another organization, but guess what I hate having to do every single year now? The same old crappy training to include active shooter response training.
To your point about file sizes - I don't think it's an insurmountable problem. For one, take some of the new viruses, etc. that are smart enough to know that they are being run in a lab environment and remain dormant. Also, footage is stored on the device connected to the remote, so it's just not on the AC SD card. Pretty sure their resolution is lower, although that may just depend on if you have TX in HD or not. Not sure, and I'm not sure it makes much of a difference given potential techniques available.
As far as data of interest produced by these drones, how many groups are using DJI products for SAR? Or infrastructure inspection, etc? That's useful information to an adversary. It would likely blow your mind to know what kind of techniques are available to retrieve data from systems with an air gap, let alone from something like a drone manufactured by a company that has direct access to the system in question by virtue of being the manufacturer. All the Chinese gov't needs to do at any given time is to tap DJI on the shoulder.
I would say that you're being way too sure of yourself. I would also say that you would not make a great candidate to work in the intelligence community, or for even a tech company like Google. You don't seem imaginative enough.