Some jobs are easy to get because they are either in high demand or there are so many jobs out there. Therefore, someone would not need to network in order to advance their career in this situation. They could do that on their merits and talents alone. However, if you are in an industry that is tight and difficult to move up into your career, you may need to use your network of friends and acquaintances to advance in your career.
Other ways that you can advance your career would be to acquire more needed up-to-date skills and education. If you always go to your friends and acquaintances to advance your career, some people might feel used and then they won’t want to help you in the future.