Did you know ArcGIS can generate contours instantaneously from your DEM? It's possible if you apply the "contour" raster function! See Help at https://pro.arcgis.com/en/pro-app/latest/help/analysis/raster-functions/contour-function.htm
Be aware that this creates a raster visualization of contours, instantaneous for the current map view - not calculated for the entire dataset. The output layer is a raster, so it still responds to the "IDENTIFY" method - this is used in a dynamic web map or app (not intended solely to be printed), and the raster contours may be more usable, more intuitive than vector contours.
