Hey!
I don't think there's a single report for this. Instead, you should check the users that are connecting more, and compare with your full list of users, to see the users that are NOT connecting. There are some reports on admin.powerplatform.com as you can read on learn.microsoft.com/.../cds-usage. Something like "Active users by Business Unit" or "Most active users performing operations". Based on this, I would check users NOT showing on such reports, and check for their licenses. Following, you can disable such users (by removing the licenses, security roles or from the associated security group).
Regards
