A Google search for me Brought up this.
Samsung Galaxy Tabs likely does not have Always On Display (AOD) because it is primarily a tablet, not a phone. While phones typically have AOD for quick information access without unlocking, tablets are less frequently designed with this feature.
Reasons for the Absence (or Less Common Use):
AOD on a large tablet screen would significantly drain the battery, which is less crucial for tablets that are often used in stationary settings.
Tablets prioritize larger screen areas and multi-tasking, and AOD might be seen as less necessary.
Its not available on my tab s9 ultra. Don't recall seeing it in settings.