Why are Service Definitions Separate Items?

[laurentideicesheet]

I see from other forums/the esri documentation that service definitions can be a very useful, versatile file. I'm wondering, though, why it's a separate item in ArcGIS Online (agol).

If it's necessary to have online with the layer, why can't this be something "embedded" in the feature layer?

I saw a forum that suggested they can be a backup-- is there a better data management solution for users to keep their content organized than these free hanging service definitions?

It can be frustrating to sift through folders of content and have to digest the duplicative service definitions in the list in addition to the ones whose titles are no longer the same as the feature they support. Further, it's redundant to authoritate both a feature layer and SD for the same thing, so that can create another content management painpoint when scrolling through libraries in agol.

I'm probably missing some obvious reasonings, so any intel is helpful!!

[DanielFox1]

 Hi @laurentideicesheet 

This may be a community post that you are aware of but it is an excellent description of the use and need for service definition files 

Solved: Keep Service Definition Files? - Esri Community

Certainly some other reasons for the files

• If you plan to republish or overwrite the layer in the future, keeping the SD file can save time.
• If you want to share the same configuration with another organization or user, the SD file is a convenient way to do that

[laurentideicesheet]

Thanks, @DanielFox1! I appreciate the concise summary in addition to pointing to greater documentation.

I do think those are handy reasons, but in terms of UI, why do they have to be separate items? It seems hefty/not intuitive for all users to have to visually sift through two files per each file.

[SimonSchütte_ct]

I agree, having the SD file as separate item is not ideal. Here is an idea I created:
Service Item: Export/Update Data as SD file - Esri Community