Currently Usage Metrics available for only 90 days. I am looking for a way to get report usage metrics data for more than 90 days to build reports for historical trends.
The other option is through Power BI Activity events API and Office 365 Power BI audit logs but for that, I need Power BI Service Admin rights which I think its highly impossible to get it because its a larger organization.
Thanks @lbendlin. I thought of doing that, but I am looking for automation to do that export data periodically and seamlessly. I do see an API released by the Power BI team recently would help to automate the export. But I am not feeling good about this architecture (i.e hitting a power bi report to export the data to the database and again generating a report using that historical data).