As far as the people around you are concerned, the personal disadvantage is that there is almost no direct employment direction in this direction. However, complex network research will give you a good background in data modeling, statistical probability, programming simulation and big data, so the flexibility of employment is actually greater. You can be a code farmer, a bank analyst, or a data scientist. It all depends on your own efforts the day after tomorrow. At least the people around me have good prospects, although employment is also varied. In the future, the job market will gradually recognize the background of this major. Now most enterprises don't know much about what this major is learning.
As a branch of system science, if you study it as applied mathematics, you will find that it exists in all walks of life like essential oil. Of course, when studying, you should pay more attention to the application of your favorite direction.
For a complex system, it is a complex problem to express the relationship between the parts of the system. Complex network is a complex network with different research objects. A complex system can be abstracted into a simple network, but it is essentially different. Complex systems mainly focus on the laws and phenomena of energy and material flow between components, while complex networks mainly focus on the statistical characteristics and important positions of nodes in the network. You can simply understand that complex systems are more detailed and specific, and complex networks are mainly trend research.