Inedible as in anything that isn’t food (ranging from something that would be dangerous, like glass, poisonous plants, or uranium, to something that is safe to eat but unpleasant with no nutritional value, like cardboard.) Eating the thing will be safe and painless.
If humans ate through photosynthesis, the capitalists would have already found a way to monetize access to sunlight
We’d have a Dyson sphere in 6-8 months.