Unlike Android, where downloading an APK file from any source is trivial, iOS is a walled garden. The official App Store offers no "previous version" button. To install an old WhatsApp version, an iPhone user must acquire a legacy file—the app's installer. This file must then be sideloaded onto the device.
The primary drivers for downgrading WhatsApp are not malicious but deeply practical or sentimental. First, plays a critical role. Apple’s iOS updates are notorious for rendering older devices sluggish. A user holding an iPhone 5s or 6, for instance, may find that newer WhatsApp versions (which require iOS 14 or later) are incompatible or cause severe performance lag. An older version, built for a previous iOS, may run smoothly, offering a final lifeline for functional hardware.
Third, concerns on newer devices can trigger a downgrade attempt. A buggy update that drains battery or fails to send notifications reliably may push users to seek a known stable "golden master" version from the past, bypassing the problematic release while awaiting a fix.