Cyanides have great, and often irreplaceable, industrial use. Your phone's gold coating is made using cyanides, and the same goes for laptops or headphone cables. Your car tires are more efficient because cyanide is used in the production of a vulcanization accelerator, a compound called DPG, which allows the rubber to remain solid and retain its shape.
Cyanide group is also part of new-age fumigant EDN which is harmless to the ozone layer and environment. They are also crucial for modern gold mining and precursors for many allergy and antidepressant drugs. Do we need to continue?