[the_af]

I think you're mistaken about this, because you're stuck in previous eras where the technological gap between "the people" and those in power was manageable; but now it's far wider, and will only get even greater.

Also, no common people are needed, and the ultrarich only compete among themselves. You only need serfs if those serfs can give you something your vast robot armies and robot workers cannot give you, which won't be the case in the dystopian future.

As for nuclear bombs: not needed. You can just starve people to death if you own all the land and all the resources, and you can use neutron bombs which are far cleaner than nuclear bombs, or given enough resources you can engineer a plague/bioweapon that just targets other people and not you.

There's be absolutely NO reason to keep anyone alive, and some guys with ARs won't be able to resist.

It's unwise to draw lessons from history about past conflicts and revolutions, since this wouldn't resemble them at all. At no point in history was there ever a situation where the ultrarich didn't need serfs at all.