Same as any other economic system: power is usually concentrated around a very small group of people. In socialism and communism, that concentration typically occurs within the party leadership or central planning apparatus.
However, in free-market capitalism, anyone is allowed to participate in capital formation and accumulation. Ownership is not formally restricted to a political class. Entry into markets is open in principle (unless it stops being a free market), and capital allocation is decentralized through free and voluntary exchange rather than administrative decree.
That does not mean capitalism eliminates power concentration, as Wealth can accumulate and translate into political influence. But the mechanism of power differs: In centrally planned systems, control flows from political authority. In market systems, control flows from voluntary transactions and competitive success.
> anyone is allowed to participate in capital formation and accumulation
In the same sense that nobody is allowed to sleep under a bridge.
I don't follow. Even now there is nothing preventing anyone here from making something for millions of dollars. While VC capital is closed to a select few, a person in a garage can still make it big.
Communist counties tend to gate keep even more. To the point that it is entirely who you know, with little concern to what you do.
> Even now there is nothing preventing anyone here from making something for millions of dollars.
Any one person might. But the system is setup such that's it's almost impossible for everyone to do well.
> Communist counties tend to gate keep even more. To the point that it is entirely who you know, with little concern to what you do.
And in capitalist countries, it's how much money you have. Swings and roundabouts.
> Same as any other economic system
Only if you limit yourself "capitalism" and "communism" as the two economic systems you are are considering. What we should be doing is noticing that these two systems fail in very similar ways (concentration of power in a small group of people), and think about what kind of system might not fail in that way.