Henry Ford created the charcoal briquette from the wood scraps and sawdust from his car factory. Ford found that he could use the charcoal for a clean smoke free source of heat. The keywords here are smoke free. Remember that the secret to great BBQ meat and other food is smoke. Ford however, was only interested in heat production and not BBQ flavor.
E.G. Kingsford bought the invention and put the charcoal briquette into commercial production. The initial purpose of the charcoal briquette was for heat in stoves, heaters etc. Then people started to use it for outdoor cooking and hence the charcoal BBQ came into being. The only problem was that there was no wood flavor in the barbecued food because there was no real wood smoke to flavor the food. A while later, the gas BBQ grill was invented because gas was also a clean source of heat and provided the same flavor as charcoal. Both the charcoal and gas barbecue grills provide heat but still need a source of wood smoke to add flavor to the barbecued food.