Why is transdisciplinarity stressed?

A transdisciplinary approach is important because it allows various professionals to work on a single case/problem without even knowing each other, exchanging information or being familiar with the whole situation.

Example 1: You have fallen ill. Your diagnosis is made by a physician. Your bathroom and kitchen need remodeling because of your illness. If you are located abroad, a translator will translate your medical report. The translation is delivered to your insurance company by the post office. Your insurance company decides whether to approve your claim or not. A nurse makes a house call on you. You hire an architect to design the necessary adjustments. Various service providers perform the relevant adjustments. You go on living with your illness.
Each of the above-mentioned professionals does his part independently from others. Your diagnosis is not relevant for the work performed by the translator. Your physician has no interest in knowing how you will access your bathroom or cook. The insurance company does not care which or how many physicians have examined you. The various service providers working on your home adjustments do not need to know that you are ill at all.

Example 2: You have decided to take a vacation. The travel agency has provided you with the information regarding your travelling and accommodation arrangements, as well as regarding the offer of recreational activities and entertainment events in the destination. You and your friend select the clothes you will bring with you, or your mom packs your suitcase for you. The agency does not have the information about who has packed your clothes, and your mom does not always need to know where you're going!