https://hardcover.app/@{username}/stats shows a preview of stats and a banner notifying:

We still have a bunch of work to do on these to match our vision, but we wanted you to see a preview while in the meantime!  
  
Some data in here might be slightly off, or incomplete. We're working on it  

It would be great to have resolving the issues / releasing a fully functional statistics feature / page on the roadmap!