Here is a feature that I and many others have been waiting for a long time; see the privileges a user has for a record and here is the best bit, how they obtained those privileges! But this is for Dynamics 365 online only.
The feature called Check Access was added in one of the Nov 2020 updates and is described at https://docs.microsoft.com/en-gb/powerapps/user/access-checker.
What I especially like is that it shows if the user obtained privileges using any of the following:
- Owning the record
- Access via a security role (directly to the user or via team membership
- Hierarchy access
And even better, if you have the System Administrator role you can check the access for other users!