Electronic Engineering is the branch of Engineering that uses the characteristics of electron or charge carriers to design the devices, machines, components for the ease of human being. The 19th and 20th centuries are considered the centuries of technology. As I think it is only because of electronic Engineering.
Though other disciplines of Engineering also play a vital role for the luxurious life of human being, for the proper application of other disciplines of Engineering Electronic Engineering has become essential.
For example if a Mechanical Engineer can design a high speed air craft, if he succeeded then for proper controlling he needs help of an Electronic Engineer. Without electronic Engineer it would not appear to be a good design.