It did attain some high proficiency. It both beat a Go master, and played at a master level (where 'master' = professional dan rating). It wasn't assessed for a ranking, but beat a 2p-dan player 5-0. That's not a 'low ranked player' - I suspect you don't know much about Go.

We'll see in March how it does against a 9p.

Your comment was a perfect example of the superhuman fallacy - where a 3p+ AI becomes 'low ranked'.