ALL user activities in Power BI should be logged for auditing purposes, including datasets accessed, reports/dashboards accessed, and especially data exports performed. The audit data should be accessible as a dataset to build reports against as well as easily exportable / downloadable.
You should be able to use the audit log data as a source to create your own reports. Currently, all you can do is dump the log from excel. I should be able to use PowerBI to easily monitor the environment. It's great you can look at an individual dashboard, but doesn't really give an admin the level of info needed.