The Galaxy S8 was released on the 24 April 2017^[1], which marks the beginning of its update period. On the 3 December 2019, the One UI 2 (Android 10) was released, a next version of the operating system, which not made available for the Galaxy S8, thus leaving Galaxy S8 on the the previous version of the operating system, the One UI 1 (Android 9)^[2]. This date marks the end of what we consider its update lifetime.

These two dates are 2 full years and 7 full months apart, which gives it F tier.