Thieves don't care about what most people do! They care about what some people do. Most people lock their doors. Some accidentally leave them open one day. That's what thieves look for.
Many people backup everything, including email files, financial documents, personal information, which can often be used to deduce passwords and bank accounts. Their only concern is to protect their data from the main internal drive failures; not from spies.
And what would the Chinese do with that? I’ll tell you: not a damn thing. That’s always the problem with paranoia, when push comes to shove you’re not worth the effort you think they’re putting in to steal your stuff.