To make this work, the recurring event’s Thing should be set to User. You’d need to “set recurring event (weekly)” on every user. So, perhaps as a part of their sign-ups flow, this action is run and is scheduled to start on the next upcoming Sunday.
The user value in the “Set RE” action would be “Current User.”
Then, in the RE itself, your workflow would look something like:
Create a weekly log with values averaged from Current Workflow User’s daily logs
Make a Change to Current Workflow User: Weekly logs list add result of step 1.