In order to save battery life while pushing all of those pixels, Apple is pulling a pretty crazy trick with the screen. It’s refreshing the screen 30 times per second (30z) when it’s static and you’re not touching it.
That’s half of the standard 60hz that you’ll see on other iPads. Every 4 milliseconds, it polls for screen or touch activity. If it sees any, it transitions back to 60hz and animates fluidly.
It’s a clever trick, and it pays off.
My battery typically lasts around 2 days on WiFi with some sketching, watching Daniel of House Tiger with my daughter and doing some typing and browsing in split-screen.
That is one clever little trick.