Quantum supremacy just means that a quantum computer is better than a classical computer at solving some (toy) task, not that one country's quantum computer is better than another country's.

Just keep telling yourself that.

Is there evidence to your claim, or are you just partaking in the incredibly banal "China is going to overtake us in ____" doomsday porn?

I see you missed the announcement last week. Whether to believe it is up to you.

"Mine is bigger!" does not define quantum supremacy. In particular, IBM does not claim to have performed any computations with theirs. By what they do report, that is because it cannot do any, yet.