I'm not being dense here - I really thought there weren't? Like the core problem with ag as a business is that it's very low margin and it's extremely hard to make money.

I can only think of a handful: marijuana, fancy tomatoes at Whole Foods, maybe coffee or vanilla (?) beans... but even there, notice how there's either fierce competitive pressure, or it's possible to easily overwhelm the market (vanilla beans have to compete against synthetics). I mean there are surely some I'm forgetting, but it's a small number, and I thought that deterred VC investment.

For your staples - corn, soy - that's still much cheaper to grow outdoors, so hydroponics can't win that market.