A number of applications to transfer files have moved the control out of the network for various reasons. UDT, TFTP are two UDP only examples. Torrents can be UDP or TCP.
For most the people working in IT the protocol does not matter except to update filters. For those building specific applications or the networks that support those applications the understanding is often critical.
The problem with most certifications is that it is a paper test. This is a compromise to make the system easy to confirm pass / fail. The alternatives are much more expensive from a resource perspective.