Android 9.0 requires more RAM and processing power than 4.4.2. Devices with less than 2GB of RAM may perform very poorly on newer versions. Security Support:
This is the only way to get Android 9.0 on a KitKat device. This involves wiping the manufacturer’s software and replacing it with a community-built version of Android. upgrade android 4.4.2 to 9.0
Upgrading a device from Android 4.4.2 (KitKat) Android 9.0 (Pie) Android 9
Download the and GApps (Google Apps) package compatible with your device's architecture (ARM/ARM64). In TWRP, tap Install and select the ROM zip file. upgrade android 4.4.2 to 9.0
Surprisingly, well-optimized Android 9.0 custom ROMs can run faster on old hardware than KitKat, thanks to Project Treble (backported) and improved memory management.