In many cases it's necessary to have advanced style for hosted feature layers on ArcGIS Online, whose features are collected and updated in the field.
Nowadays it's not possible create advanced styles for feature layers on ArcGIS Online. Many Utilities and Communications companies need complex simbology in maps that are used in field works. This maps have to be made with Feature Layers, they cannot be tile maps beaceuse they changue very often.
It would be very useful to be able create advanced styles for line and polygon features, using any of the styles you can find in ArcMap or Feature Class representations for roads, highways, boundaries, kind of surfaces, and so on.
I attach a document with a case.