Even with an old version, WhatsApp servers may completely refuse connection to old versions at any time. Recommendation:
If you manage to install a version of WhatsApp that was compatible with KitKat (e.g., a version from 2018), you will likely face another issue: WhatsApp forces users to update to the latest version to use the service. If you install an old APK, the app may refuse to verify your phone number, rendering it useless. whatsapp apk for android 4.4.4
Even with an old version, WhatsApp servers may completely refuse connection to old versions at any time. Recommendation:
If you manage to install a version of WhatsApp that was compatible with KitKat (e.g., a version from 2018), you will likely face another issue: WhatsApp forces users to update to the latest version to use the service. If you install an old APK, the app may refuse to verify your phone number, rendering it useless.