As the Guild of Guardians Demo does not contain optimisations still ahead, the minimum requirements to run fluently are higher than they will be for the next versions.
The following devices are recommended for best performance. Mid-tier, current-gen Android phones, current or slightly older flagship devices, including -
iOS
iPhone 10 or newer, recommended iPads: iPad Pro 12.9′′ (5th Gen 2021), iPad Pro 11′′ (3rd Gen 2021), iPad Air 10.9′′ (5th Gen 2022), iPad 10.2′′ (9th Gen 2021), iPad Mini 8.3′′ (6th Gen 2021)
Android
Samsung S10 / Google Pixel 4 or newer, Xiaomi Black Shark Series, LG W41 series.