The primary mission of the US navy globally is to guarantee freedom of navigation for everyone in international waters. That includes for shipping to and from China. The Chinese know this very well. The truth is Chinese and US commercial and strategic interests align almost completely in practice because their economies complement each other much more than they compete and their strategic dependencies are mostly shared (Gulf oil being a biggie), the problems are political.

They're major political problems for sure and they lead to strong economic rivalry for geopolitical reasons, but take away the political dimension and they'd be natural allies, IMHO. It's the same way that Japan and the USA went from being direct competitors to natural allies after WW2. Before WW2 that would have been unimaginable, after WW2 it became obvious. I think it's the same with China.

Also Russia actually, it's why the Ukraine invasion caught the USA completely by surprise. They just don't see what Russia could possibly gain from it because they view the world in commercial terms. If Russia was a liberal democracy them and the USA would be best friends ever, but authoritarian regimes must have enemies in order to justify their repression.

You cannot speak coherently about geopolitics without discussing currency politics and financial hegemony. What defines US geopolitical relationships is not whether a country is "authoritarian" but how it relates to the petrodollar/IMF/World Bank global financial system. A government can behave however it wants and never be bothered by the US as long as it submits its economy to this system. This explains why some oil-rich countries are sworn enemies of the US and some aren't much better than "freedom and democracy".

What defines China specifically as a malign actor from the US perspective is that it is offering countries outside the West a second choice for how to finance and pursue development. The mere presence of this competition is a mortal threat to the entire established order.