Use of the term capitalism has become widespread(1).
When we say “capitalism,” what we are really talking about is social and cultural.
Capitalism is a system that is participated in by almost the whole of the population. It may be seen as cultural. It is not simply a system of aristocrats engaging in their affairs. It is a system in which everyone is participating, even if only by buying things in stores.
(note 1): this was not the case in, for example, the 1930s.