Both have their own benefits and drawbacks. It can depend on the nature of the project, budget, and other so many things.
Hiring a developer can be cost-effective, quick decision-making, and more flexible but it can also be limited expertise, risk of dependency, and slower development. On the other hand, Hiring a team can be costly, and delay in decision making but it can be more efficient, and faster development.

so we can say that it depends on various factors which you should consider before making a decision.