I'm glad you mentioned history because when I wrote my response I was going to say "unipolarism isn't natural in a globalized and interconnected world" but I decided not to. Since the world became interconnected unipolarism can only occur if there's major collapse of another major power. When the world stabilizes and the inevitable growth ensues then it becomes harder to sustain unipolarism.Unipolarism within communication range IS the natural state and has been for most of Chinese history. China did not come to believe unification is paramount because Chinese culture believes in multipolarity.
In practice US is not in a position to challenge China as the unipolar power at this point, GDP measures transaction volume, not econmic power, Chinese production, consumption and talent pool all dwarfs America even today and the gap is only getting wider. What US has is a desire to be a pole, and as such they pretend transaction volume is economic power, while China has no desire to bring others down, so China let them. This pretense of multipolarity can hold so long as America does not actually try to wield power, but as their recent trade war demonstrated, the moment they try to wield it, they get promptly reminded who has the cards.
And how China views itself is very important as it indicates what China will do, for countries that has no aspirations to be a pole this information is not very important, but for countries that do have aspirations, its very important for them to understand China has no intention of making it easy, or possible.
Unless China completely collapses the US will never be in a position to challenge China as a unipolar power. That era has exited stage left, the Americans know it, the Chinese know it and everybody knows it. What we're witnessing is the west panicking and lashing out because the power they once had is slipping away from them.