I created a Permission Set and made one change on it: System Permission: "View All Records"
I gave it to a User with Standard Profile.
When I tested as this user, it could Update and Delete records of Account, Lead, etc. This doesn't work for me. I want Read-only across the board.
So I changed the User to "Minimal" profile, where all Object Permissions are set to "No access". It still has the Permission Set.
Now, when I login as the User, objects do not appear in the Wafer (object explorer).
What else do I need to configure to truly have Read only to all records in Salesforce?