While editing a poly in Collector, I essentially created a mass of vertice spaghetti, when I tried to edit and delete these vertices in AGOL it was one at a time, if the pointer would even bring up the delete option. Is there a way to mass delete vertices in AGOL or do I need to open the layer in Pro or 10.5 and do the editing there?
Open it in ArcGIS Pro and edit.
On the Edit ribbon, select the feature, Right-Click for Vertices, then select the vertices from the Modify Features Pane to delete.