For another comparison, top world class chess players will have solid odds to beat Leela Chess Zero when given a knight odds handicap (Leela Chess Zero starts with 1 fewer knight). For human vs human, I think this would be somewhere in the ballpark of the ~10,000th best chess player having fair odds against Magnus.

I wonder if this means the best Go play is closer to theoretically perfect play or if it just happened the current computer methods didn't manage to get much farther than humans. Go has vastly more valid games but also a simpler ruleset, so I'm not sure if there is really a good way to tell beyond "keep trying and find out"?