The ones who actually did it (Russia) ended up worse off, but workers everywhere else in the world gained, because the elite became more willing to let go of certain privileges to pacify the working class.

The goal of threatening to kill someone isn't to murder them for the sake of murder, it's to negotiate with them from the fairly sensible starting point of "give me what you want or I'll kill you". If what they want is "fair wages and a decent life," that seems reasonable enough.