What a good freelancer is genuinely good at
A skilled freelance designer or developer can be excellent value, especially for a narrow, well-defined job: a landing page redesign, a specific technical fix, a small site for a project that will not grow much. You get direct access to the person doing the work, no account manager in between, and often a lower price than an agency for the same hours.
Freelancers are the right call when you already know precisely what you want built, you have the time and patience to manage the project (answering questions, chasing timelines, reviewing drafts), and you are comfortable with the risk that comes from depending on one person's availability. If that person gets busy, sick, or takes another client, your project waits.
The trade-off is consistency. A freelancer's rates, availability, and even quality can shift project to project. You are hiring a person, not a process, and a person has good weeks and bad ones.