ArcGIS Living Atlas elevation layers were recently updated with lidar-derived, high-resolution elevation datasets. In the U.S., these updates were derived from expanded coverage of USGS 3DEP 1-meter DTM’s adding approximately 388,000 sq kms (~ 149807 sq miles) of new coverage.
Other parts of the world also received updates. For all the details, see High resolution data updates to Living Atlas elevation layers.
For elevation coverage details and extents, view the Elevation Coverage Map.