> While it's true that banks can exist outside capitalism, capitalists generally can't.

That's not really true; people who own and profit from their ownership of the means of production exist in feudal economies; the fact that their ownership of the means of production is a sonetimes a consequence of rights associated with land tenure and, whether or not that is the case, not marketable or less freely so than under capitalism the capital, makes the system not capitalism, but doesn't make the owners of capital not capitalists.

Capitalists qua capitalists aren’t the ruling class outside of capitalism (though being a capitalist was also a subordinate part of being part of the labded aristocracy, and control of certain elements of the means of production was connected to land tenure), but they still can exist. Capitalism as a system is mostly a result of the non-landholding capitalists progressively leveraging their existing wealth to gain more systemic advantage (at the express of the landed aristocracy) than they enjoyed in pre-capitalist economies.

If you separate capitalists and landlords out as different classes (in the Georgist sense) then you can say that landlords have extracted rent for far longer than capitalists have been around; it took the Industrial Revolution to move from the guild-based master and apprentice model to a capital-based owner and worker model of production.

That's exactly my point. It's clear both from banking history as well as general history and experience living in a communist country for a while.