Sure, Nike can sell them shoes, but anything which involves free expression is certainly not welcome. So, in practice, many technology and social media companies are effectively banned.
Uber is not banned from China. They had a large business in China, but they faced strong competition from Didi. They ended up selling their operations to Didi in exchange for a stake in the Didi.
The companies that are banned in China are the companies that do not agree to censor political content. That's where you get Facebook, Google, Twitter, etc. not being able to operate in China.
Western companies have a massive presence in China - far greater than the presence that Chinese companies have in the West. The top three auto brands in China are Volkswagen, Honda and Toyota. China is the world's 2nd largest aviation market, and Boeing and Airbus dominate the Chinese market. American restaurants, such as Starbucks, McDonald's and KFC, are everywhere in China. Chinese malls are filled with American, European and Japanese brands. Up until the trade war began, most Chinese people strongly preferred foreign brands like Apple - though I think this is changing, due to the hounding of companies like Huawei and TikTok by the US government.
The strange thing is that most Westerners believe that China shuts out foreign companies, and it's difficult to even begin to express just how wrong that impression is. China's development was driven by foreign capital - to a large extent meaning foreign companies entering China either to manufacture there or to sell to Chinese consumers. As a result, foreign companies have a huge presence in China.
