The very important Fillet Tool Creating a fillet curve connecting between two lines—Help | ArcGIS Desktop appears to be missing from Pro (or, if this is implemented, I can find it?). As discussed in Where are the fillet, trim, and extend tools in ArcGIS Pro? For example, cartographic refinement of a road network is heavily dependent upon the Fillet Tool. But most importantly, it's in Arc, should be in Pro.
In Product Plan