Capitalism isn't an idea, like, say, socialism. Capitalism is something that arises organically in societies that allow their citizens/residents freedom.

The alternative to capitalism isn't a different economic organization. The alternative to capitalism is not-freedom. Those who say (like @api in the first post) that capitalism is dying and imply (or state) that we need an alternative, either mean to take freedom away from us, or don't know that that's what they mean.