It worked out very badly for them. See "Reign of Terror". The Revolution ended when Napoleon declared himself a hereditary monarch. Things went full circle.
I’m not arguing in favor of it, I’m just aware of how the world works.
You also seem to have forgotten France among other places where the history wasn’t as grim as Russia. Frankly nothing Russia has ever done seems to make their lot better.
I'm not overlooking anything, including the desperate circumstances that led things like the French revolution and ensuing violence. The US went through a war to be free, plenty of people died and it could have easily gone another way. If everyone followed your advice India would still belong to the UK.
I also think it's unhelpful to compare utter madness like the killing fields of Cambodia with a typical (even failed) revolution. More typical outcomes can be seen in the wake of the "Arab Spring", which arguably achieved nothing at great cost. That doesn't mean that people won't try again though, drowning people are dangerous and irrational, and I'd argue that's why leaders and people with power should work very hard to prevent those circumstances from emerging.
It didn't make anyone better off.