Accumulation of capital is in the context of ownership, yes. Capitalism is a system in which ownership of capital is indistinguishable from any other property, which makes it possible to accumulate it indefinitely. The end result, in the absence of some countervailing force (such as anti-monopoly legislation), is its concentration in the hands of a few oligopolies. Which translates to concentration of power, and strangles democracy.
Corporations are also "collective entities" (of shareholders). The real question in this case is who effectively controls the entity. If the entity represents thousands of people, but is controlled by a few, you still get oligopolies and concentration of power. Something like a co-op is another story, although even there it all depends on how its governance is structured.
Corporations are also "collective entities" (of shareholders). The real question in this case is who effectively controls the entity. If the entity represents thousands of people, but is controlled by a few, you still get oligopolies and concentration of power. Something like a co-op is another story, although even there it all depends on how its governance is structured.