Hong Kong is the only business friendly place in the world that’s genuinely independent of the US/EU transatlantic regulatory blob.

The mainland government want to keep it prosperous so will likely work to protect it from sanctions or international regulations.

If you’re a Russian oligarch it’s probably safer to keep your money in HK than Cayman or Switzerland these days. Even if you’re a petrostate sovereign wealth fund or non NATO central bank there’s some value in holding assets that can’t be frozen at will by the US treasury secretary.

You could argue that Signapaore and the UAE compete here but they have much more dependency on the west for security and diplomacy.