You're confusing having a very large population at middle income for being a developed country. China is four times larger than the largest developed nation. Even at Bulgaria-level income development, that guarantees that they'll "dominate" most aggregate measurements. Doesn't really say anything about the success of their economy.
Even within their area of strength, manufacturing, China severely lags the liberal democracies. On a per capita basis, its manufacturing output is more than three times lower than Japan, Germany, Switzerland, Korea, Sweden or the Netherlands. It even produces less than half per capita as the US or UK, who don't even specialize in manufacturing. China is barely above Brazil or Turkey on a per capita metric.
And outside manufacturing, China's level of development is abysmal. It produces virtually nothing competitive in the service sector. China exports essentially zero financial services, media, software, professional services, or travel services. China has internally developed barely any internationally successful pharmaceuticals, Internet properties, film or television franchises, marketable brand names, banking franchises, auto models, jet aircraft, or microprocessors.
The success of China's tech companies is almost certainly because the Chinese government doesn't allow much stronger American competitors to enter the market. The reason Europe doesn't have a Baidu is because Google was allowed to compete in Europe. The entire Chinese tech industry's sole global success has been TikTok. The inability to compete on the global market proves that the Chinese tech industry does not measure up to their American counterparts. This is corroborated by the fact that not a single major software project has ever come out of China.