Let's use the analogy of your car engine. For you to be able to drive your car successfully, all the parts of the engine must work in sync. Even if one part is malfunctioning or worn out, it can either make your car splitter and splatter, or completely halt it or worse, cause an accident.
The problem with malfunctioning or worn out parts is that even if they don't cause you an immediate problem, they begin to tax the perfectly functioning parts. After a while, many more functions begin to malfunction.
The same happens with your business. A couple of ill-functioning processes can drag down the performance of other, well-functioning processes. It is like participating in a race with a few kilograms of rocks tied to your feet.
Why do some processes work and some processes don't? In most of the cases, it is lack of experience or lack of a different perspective.
After all, there are thousands of successful businesses. How do those businesses become successful? There is a synergy in all their processes. All their functions are finely tuned. Whether it is finance, the supply chain, the HR, sales and marketing, resource management, inventory management, information technology or compliance, every component of the business works as a complete whole. If this "completeness" is lacking, it becomes difficult for your business to prosper. You are spending more time in firefighting rather than growing your business.