This is a bit of a digression, but: It's an interesting question what (if anything) that larger dynamic range
means.
One thing you'll hear people say sometimes -- I've said it myself -- is that this shows that in some sense go is a "deeper" game than chess; there's more to know and understand, more variety of possible human skill.
That might well be true. It certainly feels a more elegant game, and involves longer tactical sequences, and so forth. But this may be misleading.
Consider the game of treblechess. To play a game of treblechess, you play three games of ordinary chess and look at the overall result.
Suppose that when we play ordinary chess, I win with probability W, lose with probability L, and draw with probability D = 1-(W+L). And suppose separate games are independent of one another (which might not be true in reality, but never mind). What happens when we play treblechess?
I win 3/0 with probability W^3. I win 2.5/0.5 with probability 3W^2D, because that happens when I draw any one of our three games and win both of the other two. I win 2/1 with probability 3(W^2L+WD^2), because that happens when I win two and lose one or win one and draw two, and for each of those there are three choices for which game is which. So I win at treblechess with probability W^3 + 3(W^2(1-W)+WD^2).
I can draw by getting one each of WDL (probability 6WDL) or by drawing all three (probability D^3).
Suppose that when we play chess I win 40% of the time, draw 50% of the time, and lose 10% of the time. Then our Elo difference is about 107 points. In triplechess, I will win 65.2% of the time, draw 24.5% of the time, and lose 10.3% of the time. Our Elo difference is about 214 points.
If in ordinary chess I win 65% of the time, draw 25% of the time and lose 10% of the time -- about the same odds as for treblechess in the last example -- then our chess Elo difference is about 215 points. At treblechess I will win 84% of the time, draw 11% of the time, and lose 5% of the time, and our Elo difference will be about 375 points.
If in ordinary chess I win 15%, draw 75%, lose 10%, then our Elo difference is about 17 points; in treblechess I will win 31%, draw 49%, lose 20% and our Elo difference will be about 41 points.
Treblechess Elo differences are on the order of double ordinary chess Elo differences! Clearly treblechess is a game with twice the depth of ordinary chess!
But it isn't. It's just longer and gives more opportunities for the better player to come out ahead overall.
Go is also a longer game than chess, though of course not in the same way as treblechess is. Perhaps the larger Elo range of go is more because of that than it is because of actual deeper strategy and tactics?