During my normal usage in Linux, which includes web browsing with Firefox, video playback with Haruna Media Player (with hwdec set to auto), writing in Obsidian, and lightweight coding in Visual Studio Code and Android Studio, the tablet lasts for 6 hours.

There’s no such thing as lightweight android studio lol. The battery would likely last much longer just playing a movie at low brightness, which is usually what hardware companies do to measure and advertise battery life.