Last access date and time

There is the getunusedartifacts rest api call.  You'd have to loop through the workspaces and it return items that haven't been used in the last 30 days, along with their last access date.  At least that is what the documentation says.  I haven't tried.  I'd be interested if you find a solution as well.

https://learn.microsoft.com/en-us/rest/api/power-bi/admin/groups-get-unused-artifacts-as-admin