While the ArcGIS World Topographic Map (raster) has contours, the Vector World Topographic Map does not.
Contours seem like a good use case for Vector Tiles, but they are not there.
What is intended if you want to show contours with it? Is there another source for them.
If I were to somehow make my own vector tiles for contours or get them somewhere, I am not sure I could use them because ArcGISVectorTiledLayer appears to only allow ESRI sources - Uri or VectorTileCache.
I'm in a field where my customer base expects to see contours on a topographic map. Otherwise, it is a street map, not a topographic map.