People can grow vegetables and simply eat. But bread is way too complicated.
There is a bakers’ dozen of big steps to go from wheat into bread. And multiple special structures needed too.
Same with beer. Wine makes total sense but how do you even invent ale? How are these common foods everyone knows and uses?
I was thinking “imagine if mediveal people knew how to boil seawater and sell salt” and now I spent 20 extra minutes in the shower.
These people, they had the same brains we have now. But they largely got by on a lot of physical labor so they had a lot of time to think. And they didn’t have a lot of exterior lighting to go around and do things in the dark so they had a lot of time to experiment inside.
I think it’s easier to consider that probably every combination of everything to eat and ways to cook things has been explored in depth. Every single seed of every weed out there has been ground and tried.