Samsung's Galaxy S21 doesn't support seamless updates

Last year, a change to the Android 11 Vendor Test Suite was spotted, indicating that phones launching with Android 11 and later would be required to support so-called "seamless" updates. This feature allows a phone to install a system update while it's running and simply reboot into the new environment without any user-facing delay. Unfortunately, that hasn't panned out.
Read more: https://www.androidpolice.com/2021/01/24/samsungs-galaxy-s21-doesnt-support-seamless-updates/?source=Snapzu