Hiring an iOS developer is beneficial for creating or updating apps that run smoothly on older Apple devices. They have a deep understanding of the specific features and limitations of this operating system, ensuring optimal performance. They can also provide support and updates for apps used by customers who haven't updated their devices. Additionally, their knowledge of iOS can be invaluable for developing new apps, as they can leverage this foundation to create apps compatible with both older and newer iOS versions, reaching a wider audience.