For a number of years now, companies such as Samsung, Huawei, and Xiaomi have allowed users to customize the UI of their devices via different Themes. A similar implementation is currently offered by Sony too but it could soon disappear entirely.
Through its official forums, Sony has confirmed that the Xperia Themes feature is no longer available on its most recent flagship, the Xperia XZ3. The decision to remove the customization feature comes after the company noticed a “low usage rate.” Nevertheless, it did assure owners that wallpapers downloaded from the play store can still be used, as can the live wallpapers previously associated with themes.
Sony went on to confirm that other devices which receive the Android 9 Pie updated will not be affected by this removal and will still have access to Xperia Themes. So, at least for now, only the Xperia XZ3 is affected. However, considering the company has removed it from its latest flagship, future devices will most likely skip the feature too.