Stupid is as stupid does. Not only does this not look like the least bit enjoyable, any idiot can see the obvious dangers. My guess, since it was in Russia, that lots of Vodka was involved, by everyone involved.
Actually, it is a lot of fun, and there are dozens of Zorb runs in the United States. None of which have a deep gorge at the bottom of the hill.
In some places, you can choose a “water zorb”, where they put water into the ball with you, and it’s like a water slide.
I haven’t done one of these yet, simply because a single run is very expensive everywhere I’ve been that has them. More expensive even than the zip lines, which are usually pretty expensive, because of the insurance.
But I’ve watched videos of people doing this, and they are all having a blast. And I spoke with one woman who did it who loved it and said she’d do it again.