infants and toddlers "just have no idea what's going on" no matter how well done a video is
They can enjoy music, motion, colors, and even learn to understand what is going on. My first daughter watched https://www.babysigningtime.com/ from about 6 months (give or take a bit) and by 1 had a rather extensive signing vocabulary. At first she would watch 1 segment and gradually would watch one 30 minute episode (each episode had about 6 segments with a group of related signs in song format). The songs were catchy and the colors were flashy. Even if she was just sitting and playing and not paying full attention, I felt it was a fine musical background. Also, her watching was not always a solo activity. Many days, her and I would curl up together on the couch and watch the episode right before bed as a way to unwind. I was hoping http://www.yourbabycanread.com/ would catch her attention too, but when she wanted a show on it was almost always Signing Time.
Most people will immediately take the knee-jerk reaction and think they can't let a child watch anything. Sure, if you let the television babysit your child for hours you will have issues. Like everything else in this world, there is a need for moderation and parental involvement. In my opinion, there is nothing wrong with letting a child watch things like the previously mentioned shows, Sesame Street, Super Why, or Sid the Science Kid, so long as it is not being used as a substitute for parenting.
(I do not work for nor have any association with any of the aforementioned programming)
(Post based on empirical evidence, not a scientific study. Your mileage may vary. Perhaps my child turned out great DESPITE my efforts.)
 Mega Man 9 is an obvious counterexample. It's pretty hard for a modern day game--somewhere between MM2 and the later ones which could actually be beaten fairly easily. And it sold like hotcakes.
You enjoyed Mega Man 9, yet you could rubber band down "right" on controller number 2, hop down any hole, and become a GOD (not to mention the jumping 5x higher)... pretty much removed all challenge from the game, but allowed you to play through the level. They could also freeze the bad guys with the controller making things easier, or harder (fun to do to siblings or friends at inconvenient times) Did that ruin YOUR experience if somebody else was able to do that? Now if the complaint was "I am too weak willed to not cheat when it is so readily available", I would understand, but complaining that cheats you don't have to use ruin YOUR experience is just silly.