Again, you're misunderstanding the difference between GDP and foreign policy. China has a low GDP, which I mentioned but a giant economy. Think of it like Apple has a $1.9T market cap and 130,000 employees and Amazon has a $1.6T market cap with 800,000 employees. From a foreign policy perspective, the number of employees doesn't matter. It's only the ability to project power into other countries. China is not a developing country. It only feigns to be.
"Appear weak when you are strong, and strong when you are weak" — Sun Tzu
The problem with China, again to repeat myself, is that there is significant overlap between the economic and foreign policy interests of China. Whereas American companies only care about making more money, Chinese companies want to both make money and extend Chinese influence.
This is terrible for democracies so easily swayed by unregulated emergent technologies like social media. If all you think Russia did was leak documents, I think you far underestimate their impact. An underdog candidate without majority popular support became president by the smallest margins. Democracy only works if its influenced by people who actually care if it succeeds. Foreign influence of any kind rots it at its core. This is the goal of China and Russia (although they may approve of different candidates).
This isn't a problem of America losing its hegemony in the world. It's a problem where foreign influences help elect a leader that has led to the unnecessary deaths of more than 100K Americans. The USA is no saint but China and Russia literally seek to elevate themselves at any cost. Allowing any Chinese companies influence over American citizens is an absolute disaster. They won't simply seek to make money in the USA, they will try to extend Chinese national interests at the cost of American lives.
I'm not sure if you're the type of person simply trying to seem intelligent by arguing against the popular stance or if you truly believe what you say. In either case, I don't see why a smart person such as yourself would defend the reputation of such a country. The future will judge us based on our inaction towards the suffering of the Uighurs and Tibetans.