As the owner of a solo consulting firm, I'm an entrepreneur myself and also work with other small businesses. As I learned from my mentor Alan Weiss, the hard truth about being an entrepreneur is that, no matter what product or service you provide, your main business is marketing (not sales).
Especially for services, cold calling doesn't really work, since we are in the Attention Scarcity Age. People are bombarded with pitches, emails, social media posts, etc.
Somehow, entrepreneurs need to break out of the noise and attract prospects to come to them. The insidious thing is that this issue doesn't manifest itself right away. Most entrepreneurs have enough connections that they can attract customers for a year or two. But, then business starts to dry up and they find that they need to attract people outside their circle.
This is the hard truth of entrepreneurship: either build a pipeline to keep providing prospects, or else suffer feast or famine.