How to determine what maps are using a layer in AGOL

Question

I'm hoping to remove some large layer files from my AGOL content (layers no longer relevant or used) and I want to know what web maps are using them. 
I realize I can look at a map and see what layers are being used, but I want to do the reverse and look at a layer and see what maps are using it. 
ESRI support has advised it's not possible at this time, but they mentioned posting on here for solutions, or to encourage interest if others think this functionality would be useful.

Katie_Clark · Answer

Check out this post, hopefully it will help 🙂

https://community.esri.com/t5/arcgis-online-questions/possible-to-find-out-where-feature-layers-are/m-p/1154246#M44877

JillianStanford · Answer

Hi Melissa,

I think you could do this pretty easily with a Python notebook.

This sample is for cloning content but it contains all of the pieces for getting a reference to a feature service then looping through each web map and checking each of it's layers to see if they match the feature service.

Hope that helps!

GISMallku · Answer

I believe this may be the idea they were referring to https://community.esri.com/t5/arcgis-online-ideas/provide-a-warning-about-dependent-items-when/idi-p/934321