It would not surprise me if nation states did control 10% of exit nodes. Onion routing however, means that exit nodes alone can not deduce sources. An attacker

It would not surprise me if nation states did control 10% of exit nodes. Onion routing however, means that exit nodes alone can not deduce sources. An attacker would need to control a whole chain to know both traffic source and destination, and the most important aspect of Tor architecture is to make that as difficult as possible.