Every business is in some sense a machine. Inputs and outputs.
These are very complicated machines, with inputs driving outputs that drive inputs, etc. Some components are circular, some have more impact than others, etc.
The key as the CEO/investor is to deeply understand that machine first, and then optimize it.
Figure out what the most impactful area is to fix, and fix it, then move to the next one. When a part of the machine breaks, you go there.
This is also why founder CEOs are so often better than non-founder CEOs. They have the entire machines context in their heads. Non-founders don't, and often it takes them a long time to figure it out. Many times they also bring shortcuts to understanding the machine (business school, other businesses) that aren't relevant or have changed over time.
Find people who care deeply about understanding the machine because you can't optimize something you fundamentally don't understand.