It should not. There is exactly zero reason for all this data to leave the premises.

> For your typical ‘dumb’ home user

Well, yeah. That's the problem. There is no explanation to the dumb user why this stat is only available while connected to home network.

My solar production data is fed to my ISO so I can sell clean energy vouchers. My solar installer just called me the other day asking if I had a tree shading a panel, because production on that panel was low. There are plenty of reasons to have internet connected solar equipment.