It's this new thing called organic farming. Just came out recently ~ 12000 years ago.
Simply put, you will feed the soil instead of feeding the plant directly. Organisms in the soil will feed the plant in return.
Best thing is, just as with mixing chemicals/minerals, you could do everything yourself and even spend nothing at all if you have sources like farms, fish tanks, lakes etc. When you try to figure it all out on your own it might take forever to find the right mix, but there are some who have done it before and shared what to use and how to use it for free. I'm just lazy so I bought a ready to use product. I will see how it goes.
There are reasons, plus pros and cons for all methods, so it makes no sense to discuss what is better. All depends on what the grower prefers. I didn't try all growing methods yet, but from a smoker perspective I tried everything and prefer organic weed (unless it's totally botched). If somebody else likes hydro or whatever the most, thats totally cool with me too.