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Seattle Forrest
Besides the dad nature of that video, notice those rollers - Kreitler Hot Dogs. They are narrower. The diameter is midsize so they offer more resistance than the bigger, less than the smaller.
There is a bit of standing, no hands. Tougher stuff is stopping, jumping on and off. Riding in reverse on a fixed gear is something I could never do. But basically they take some concentration. While the parabolic don't.
My opinion about the importance of those skills is still open. I put my kid on rollers early in his single digit years. We live in SoCal so for us, rollers were for warm-up/when we couldn't ride (the train) and were not used that much.
As to the skills, I think body control is always important, but the way you ride on rollers may not be the way you want to ride on the road.
Standing on rollers <> standing on road. You just don't have the pedal force. You can put it in the 53X11 but it is not the same.