In an agency, your task goes through a manager, estimation, assignment, a queue, development, and acceptance before you see any results. Every step adds time and cost — regardless of how big or small the task is.
With me, you communicate directly with the person who writes the code. No queues and no extra layers of approval. And staff turnover in agencies is real — six months later, your project may be handed to a new person who has to dive into it from scratch.
An agency makes sense if you need a team of several specialists for a long-term project. But if your task is specific — a module, an integration, or performance optimization — an experienced independent developer will deliver faster and at a lower cost.