Growth is not one thing. It is a chain of small steps, and revenue leaks out between them. Someone has to find you, then visit, then understand what you sell, then trust you, then buy, then come back. A business can be strong at four of those and weak at one, and the weak one quietly caps everything else.
This is why owners who pour money into traffic often see nothing change. If only one in a hundred visitors buys, then doubling your traffic doubles your costs and still leaves ninety-eight people walking away. Fixing the reason they walk away is cheaper, faster, and it makes every visitor more valuable from that day forward.