And yet you can buy a Tesla in China or an iPhone or any luxury bag or or or. Plenty of brands. It's not quite as black and white as people think.
What you're talking about is social networks/messengers/news which are limited not so much for competitive reasons but national security reasons. They like to control what people see which is something a Google, Meta or X cannot guarantee.
You can very much buy US software, e.g. https://www.microsoft.com/zh-cn/microsoft-365/buy/microsoft-... etc.
You can buy a Prada bag, a Ralph Lauren sweater, the newest iPhone or Mac, a Model Y, adidas or Nikes, Adobe Photoshop... etc etc