Compost, fertilizer, and mycorrhizae.... nobody feeds the trees in a forest yet they grow tall, green, and healthy. It is the symbiosis between soil microbes, fungi, and decomposing organic materials that feeds all green flowering plants on the planet earth.
Nutrients were made by humans for convenience and marketed so heavily that eventually people forgot how to grow weed without them. God invented the process long before people got involved but it’s hard to make a lotta fast money selling worm castings and cow shit. Advertising/marketing is the culprit; people think you have to buy several bottles of chemical crap to grow quality pot but all you really need is an active soil mix. And some decent lighting....