Weaker players are more inconsistent. Someone else says Lee-plus-two stones beats Ke. I don't think me-plus-two-stones dominates someone who beats me 8:2.

So with weaker players, 8:2 is consistent with a wider range of skill gaps (measured in handicap stones). It's consistent with one player being only a little better, and it's consistent with one player being a lot better.

With two of the best players in the world, 8:2 isn't consistent with more than two stones difference between them.

So in this case, 8:2 rules out a lot of possible skill gaps, which does say a lot; in the same way that "beats me 8:2" says a lot more than "beats me 10:0".

(Alternatively we can measure skill gaps in points. Games between weak players will often be decided by tens of points. Games between strong players will be decided by a handful. 8:2 between Lee and Ke suggests their points gap is smaller than between two amateurs who get 8:2.)