"Won't a revolution eventually lead to inequality again?"
This question arises from a superficial examination of many of the world's revolutions - from the French to the Russian and beyond.
But there is a fundamental difference between the French Revolution and the Russian Revolution. The French Revolution was a bourgeois revolution; it established the capitalist class in France as the dominant class, as opposed to the feudal lords and the aristocracy. Bourgeois revolutions usually have as their demands things like legal equality, freedom of speech, freedom of association, parliament/congress, voting rights, etc.
Yet these demands for inequality mask a more fundamental inequality - economic inequality. As capitalism developed, more people were drawn into the cities and became impoverished workers, and the capitalists' pocketbooks swelled. So even though the capitalist and the worker are legally equal, each of their votes counts just as much, who has more influence on the politician?
All bourgeois revolutions are bound to recreate inequality precisely because the capitalists need to exploit the workers. A bourgeois revolution may smash the feudal system, but it does nothing to the class structure of society itself.
A proletarian, or workers' revolution, is an entirely different matter. When the working class takes power, who will they need to exploit? What class labors for them?
"Well a group of people will still boss everyone else around."
That's pretty unlikely if the revolution is successful. Why? First of all, the representatives of the working class, within the workers' councils, would all be immediately recallable and paid the same amount as those they represent. If these people give themselves a pay raise, then they would probably be unelected. If they refused to leave, they would have to be kicked out, with armed force if necessary. After all, the representatives are only a few, while the workers they represent are many, and they would all be armed and in workers' militias. That's why the standing army and the police must be abolished - so that the armed force in society is not monopolized by a small, exploiting minority, but rests in the hands of the majority.
And if there has been a workers' revolution, that means the masses have taken matters into their own hands, and wrested power from the hands of the capitalists. While this in itself is no guarantee, it would be a strong bulwark against the re-emergence of a class.
"So what happened in Russia then?"
In Russia, there was a workers' revolution, but it also had to carry out the tasks of a bourgeois revolution, establishing legal equality, dividing up the landlords' estates, for example. The working class was a tiny minority, surrounded on all sides by the peasantry, and without material aid from a workers' revolution in other more advanced countries, the Russian revolution was doomed.
The revolution was isolated and a dozen armies invaded to strangle the baby in its cradle. The working class of Russia ceased to exist by the end of the Civil War - and in its place, members of the Bolsheviks party and bureaucrats in the state/party apparatus had to substitute for their activity. Instead of meetings at the local soviet, government decrees were handed down, and the debates took place behind closed doors. Eventually a new ruling class did arise, the party bureaucracy led by Stalin, and subordinated the interests of the workers and peasants to their own interests.
The Russian revolution was an exceptional case, in which the working class and the Bolsheviks faced unimaginably difficult, seemingly insurmountable obstacles. A workers' revolution in today's world would be in a far better position, thanks to the increased technology, interconnection, and the immense size of the world's working class.