When your clients hire you, they’re not buying the thing you’re selling.
They’re buying the benefits of that thing. A business outcome with real value attached.
They may be fairly confident you can deliver on the scope of your work, but whether they will actually achieve the business outcome they want is a gamble.
And they are acutely aware of this fact.
Since it’s a gamble, it’s your job to make their bet less risky for them.
Avoid putting all the risk onto your clients. Specialize, prove credibility, and offer guarantees for your services.
Your work will be a lot easier to sell at high value when you do.