Let's say I have a service with a point layer feature class. And this has a related table in the service and data frame. I want users to be able to create and update the point feature class itself. But not Delete.
But I want users to be able to create, update and delete records in the related table. Or maybe a different sublayer if it was another point feature class. Is this possible? It looks like.. no? If so I will make an Idea:
Allow different editing permissions for different sublayers in a REST service. At the service level. Also would be nice as a Field Maps Designer option.
As far as I know, the short answer is "no".
You can sort of do this with View Layers, publish one view layer with the points, a second view with just the related table, then configure their separate settings as needed.
Downside is that maps and apps won't "see" the tables as being related, but you can still use the parent/child relate fields to get the layers to interact with some Arcade.
The answer is yes, but it isn't out-of-the-box functionality. What is an SOI | ArcGIS Enterprise SDK
You can do this with Hosted Feature Layers by using the Update Definition to enable a layer override. However it's NOT obvious that this change has been applied (will confuse anyone trying to update the editing settings later on). Definitely recommend doing it on the View, and not the source layer.
https://mediaspace.esri.com/media/t/1_jsnt8a3l
About 49 minutes in.
Otherwise no, it's not possible for non-hosted feature services out of the box. You need to create database views and multiple services with differing functionality or explore add-ons like the others have said.
Yes @ChristopherCounsell is right its possible if using online hosted feature services. Users will need to view the JSON to see the layer override property. Currently Capabilities which is what you are interested in, allowgeometry updates and ownership based access control can be updated per layer basis.