That's because China has strongly failed to follow trade agreements under WTO, including the TRIPS agreement (which is an international agreement protecting IP rights), SCM agreement (which prohibits state subsidies of certain trade goods), the National Treatment Principle (which mandates equal treatment of imported and locally produced goods), National Treatment and Market Access commitments (China strongly restricts foreign ownership in certain sectors of their local market, including the tech industry), etc. Mind you most of these agreements were made in the 90s, so China has had plenty of time to comply. It's a bit pointless to keep using the WTO when a country isn't going to comply anyways.
I'm not saying the US is blameless either, but with China, it's nearly shameless. In the tech industry alone, Youtube, Facebook, Instagram, WhatsApp, Twitch, Steam, LinkedIn, Dropbox, ChatGPT and Copilot, Github (partially), etc are all banned in China. Shoot, Google left a decade ago after they kept getting hacked by the Chinese government. When China was still quite poor and developing, this behavior was overlooked, but as they become a rich world power on the global stage, that's not the situation anymore.