I saw this too and it surprised me as well to see the Euro take such a small role, but I think the chart gives a skewed picture. It almost seems as if Europe plays a tiny role in the crypto markets but I think a lot of european traders probably are using the USD(T) to trade. I know I've rarely used anything Euro-related in crypto and basically do all my trading, calculating and whatnot in either USD or BTC.
Also it seems weird if Europe is so small by comparison - I feel like Europe overall is pretty positive towards crypto and I frequently read reports of how many dutchies hold crypto (over half a million households I think?)
But yes the chart is pretty!