This is a field where a little knowledge, combined with imagination, might bring big results.
It's true you can carry out tons of practical electronics without a knowledge of quantum physics...
However the world is waiting for someone to find the secret to several breakthroughs.
Many are associated with power generation.
We will develop new electronic devices based on application of quantum mechanics. Some of the electronic devices in our parts bins are put to use everyday in many practical ways, yet which defy understanding of their behavior. I once heard, for instance, that the tunneling diode works because electrons are said to 'tunnel' from one side of a junction to the other side, yet their method of travel cannot be explained. (I may be behind the times on this.)
Below is a short list of examples of how the electronics engineer could change the world through a knowledge of quantum mechanics, quantum physics, particle physics, etc.
* Make photovoltaic panels more efficient at producing electricity.
* Store greater amounts of energy in batteries.
* Achieve electric power transmission without wires.
* Achieve superconductivity at room temperature.
* The impossible dreams. Example, gravity may or may not be intrinsically connected to magnetism/ electromagnetism/ electronics. However to find the secret of antigravity is likely to depend on knowledge in those areas, along with a knowledge of quantum physics.
* To develop cold fusion. It may or may not require a support system of megawatt-rated electrical equipment. It may or may not require the input of enormous electrical power to initiate the fusion. However it's likely to require knowledge of both electronics and quantum physics.
* Medical breakthroughs. One area of big interest is nanobots. Today science fiction, tomorrow real life. Self-powered, with onboard sensors, computers, telemetry, etc., and directed to seek out pathogens, cancer cells, etc., and to destroy them. Self-destructing when their task is done. The degree of miniaturization required will require knowledge of electronics at the atomic scale, and perhaps a new and unconventional concept of electronics.
* Develop methods of propulsion using safe and manageable sub-atomic energy. Practical methods, that is.
* Invent a force field. For personal defense, or large-scale defense.
All of the above breakthroughs are likely to be achieved by someone with knowledge of electronics as well as quantum physics.