For example, for Westworld  I had to track down original 1970s journal articles about the making of the film and manuals for long dead hardware. For The Terminator  I had to buy scanned copies of Nibble magazine and then track down the exact references to what's on screen.
All of the research in my videos is very carefully done and original and I make sure that what I am saying is accurate. That takes time. So a three minute video might be hours and hours of work even before writing the script, getting suitable screenshots and recording the video.
One day I'll have time...