You have to keep thinking independently of what everyone else is doing and evolve your planning strategy constantly. You should never rely on having one fixed source of income because your job could disappear tomorrow and if you have multiple sources of income you can either 1) give yourself a backup plan or 2) enable yourself to reach financial freedom much earlier than other people might. You have to be aware that every economy goes through a boom and bust cycle, so you need to make the most of the good times while they are available and ideally scale up your employment prospects during that time. Never stop moving or you might find someone else stepping in to your shoes.
The more sources of income the better because we never predict how steady jobs will be tomorrow. The mindset of the rich will always be thinking about how to make a lot of money and they make coordinated plans to achieve it. It takes planning as you said because life without a plan will never work and how we can increase our interest in continuing to obtain things in a much better way.
Relying on one source of income will not give you the opportunity to reach the maximum level of freedom. Humans always think about how to earn and stop at a certain point and not moving will only slow down the successful life we want.