I am consuming way too many credits.
I need to delete services but for many of those services I cannot say if a web application was created.
So, I am not able to know whether I can safely delete it.
Is there a way I can know how many web maps and app are using that service?
I think it would be a case of using the API to list the services in every web map, then list all of your current services and do a diff against them. You could also check against the view count for each web map and compare against say a week interval to give an indication of web maps not being used, then identify the services within those.
Someone in one of the live esri UC sessions asked this yesterday. Esri responded it's in the roadmap to build out something like this but currently not available. They did mention there are some 3rd party esri partner solutions for this.