The adjective interdisciplinary is most often used in educational circles when researchers from two or more disciplines pool their approaches and modify them so that they are better suited to the problem at hand.--Wikipedia
We live in the 21st century. The things that surround us are the artifacts of hundreds of years of people making stuff. We have language, literature, art. We have physics, electricity, and televisions. We have roads, stop signs, and crosswalks. We have plastic bottles, Gatorade, and recycling plants.
How many of these things could be produced by a sole practitioner of a single discipline?
It turns out most of the simple stuff got solved a long time ago. There was an age when a carpenter, using nothing but his knowledge of woodworking, could crank out a furniture set for a family. I guess that's still true, but how much furniture is hand made anymore? Now we design for manufacture, design for shipping, design in line with the popular stylistic tastes. If you're going to be your own carpenter you probably also need to have a good business sense and understand how to file your taxes.
How many people does it take to design something of larger complexity - a car, for instance. The construction of the frame to deal with stress and crunch zones to protect passengers, the chemical composition of the tires to resist wear and grip the road in inclement conditions, the programming of the microcontrollers that fire the airbags and blink the turn signals, the optimization of the drive train to maximize fuel economy, the design of the body of the car to be aesthetically pleasing. Designers talk to electrical engineers talk to mechanical engineers talk to chemical engineers talk to machinists talk to salespeople and marketing talk to customers talk to plant operators talk to governmental regulation agencies.
It's All a System
We live in the most complicated system man has ever produced. I have borrowed a picture of it from Wikipedia. Pretend the part that says "System" means "everything man has ever created or done" and the part that says "Surroundings" means "stuff not on Earth" and you have a rough idea of it.
Now, we can of course define smaller sections of the System that encompasses humanity and its endeavors, but if we draw anything sufficiently large, we are going to draw a box around people with fundamentally different fields and views. The era of "Mechanical Engineer" vs. "Electrical Engineer" and "Producer" vs. "Consumer" is fading away. Nowadays, people have a stronger understanding of more fields. Biology involves Chemistry, Chemistry involves Physics, Physics involves Mathematics, Mathematics ground Computer Science, Computer Science drives the computer you're reading this on now.
If you wanted to do disciplinary design, it's too late.