Initially, WhatsApp had only two primary sections—Chats and Calls—both placed on the top bar, making them difficult to access, especially for one-handed use.

At the time, this design choice made sense, as smartphones were smaller, and user interactions within the app were relatively straightforward. With just two main sections, placing navigation at the top allowed for a clean and uncluttered interface, reducing distractions and maintaining a familiar layout.

This approach also aligned with standard UI conventions, where apps with fewer than three main sections typically avoided bottom navigation bars to maintain simplicity. The focus was on providing a minimalistic, efficient experience for users who primarily engaged in text-based conversations and voice calls.

However, as WhatsApp evolved, the top-bar navigation struggled to accommodate its expanding feature set. The introduction of new functionalities, such as media sharing and business tools, increased user interaction beyond simple messaging and calling. Navigating between sections became less intuitive, especially on larger screens, making it clear that a redesign was necessary to enhance accessibility and usability.