Yet, we do. Assange would not be able to change that. And really, it is about as "none of our business" as any major criminal activity you could think of.

It is Russians' business, technically, but in practice regular Russians are no better equipped to act on information about it than we are.

The West would have legal standing to sanction, freeze the assets of, and arrest employees of oligarchs who use their wealth to commit financial crimes in the West. So yes, having leaks from Russia is very useful.