True, fruit and nut-based food forests, like those in the Pacific Northwest [1], seem to provide a significant, sustainable food source. Berries make a nice dessert + vitamins a few times a year.

Historically here in Maine, the core diet seems to have been seafood, freshwater fish, maize, Capreolinae, game birds, eggs, honey, roots, and greens. While only a tiny fraction of fish/seafood remain, deer are over-populated and make a fine sustainable food source, the limitation mostly being the contemporary appetite for venison.

1. https://www.smithsonianmag.com/smart-news/indigenous-peoples...