It's basically because George Soros sees only three major power blocs in the world. His team, which is the Globalists/The "West", the China-Russia Bloc and Islam. Since Putin and Xi have this horrible habit of nationalizing and subverting private enterprise and successful multinantionals and corporations to their will, of course George Soros is against them. He wants an Open Society in which his corporate pals and him can influence governments, policy and society how they want and bring their control over the world, including over those recalcitrant Russian and Chinese power blocs and the pesky Muslims.
It's a variation of a popular Conservative POV of the three power blocs, like how Dennis Prager states there's three power groups. Conservatives/Traditionalists, the Left and Islam.
George Soros doesn't even give oxygen to the size or scale of Conservatism or the Right in the West except as something to subvert which he does through financing campaigns big and small across America, and supporting non-profits and whatever other influence he (and it's important its not just him, but all of the Globalists) to marginalize them. And people call it all sorts of things which is usually illustrative of how much they feel the Globalists actions drift into conspiracy or Supervillain territory. Some just call them Globalists, Liberalism or Neo-Liberalism and others go deeper and say its One World Government/NWO or the GLOBOHOMO something something, and some take the lazy route and say it's all just those fucking Jews again.
I think some of the Globalists are completely sociopathic and amoral assholes who are more like Alex Jones says in they wish they could wipe out all of the pesky poor people and Reset it all, but I figure most just love money, want to keep making money (or in the case of American politicians the balance tends to be skewed more towards power and less towards money) and actually think everyone would be better off embracing the rule of the rich and powerful elite and find it loathsome that Putin and Xi want to make money the wrong way and not be in their Club. So of course George Soros thinks President Xi is the greatest threat. They don't want the fucking Chinese Communist Party replacing them as the Global Elite or severely curbing their worldwide power and influence. Their basic slogan is basically
"Xi will not replace us."
Anyways I'm rambling now. What are we talking about?