A lot to address here...
Extractions can be made with or without chemical solvents. Either way can produce a safe extract. It is a great way to glean the trichomes from an otherwise undesirable product (trim and leaves). Crossbreeding for certain traits, such as potency, allows growers to grow more product in less space with less water and energy consumption. Hydroponics deliver the necessary nutrients, can be done organically and saves water when done properly. The ruderalis shown in the photo will require much more smoke inhalation and won't get you high...