Tell that to China that does not allow Facebook, Instagram and Youtube in China. They have access to 400 million americans but we can't have access to 1 billion Chinese people? China was running a long time a go
Western platforms were losing to Chinese ones in PRC before they were blocked. When hammer came down to enforce onerous human moderation on ALL platforms in PRC, western platforms chose not to comply, because adding layer of human moderation at the time wasn't worth the cost/optics. This was a time when PRC domestic platforms had 10,000s of humans in the loop and western ones had essentially none. Why do you think Facebook and Google both had internal projects to re-enter PRC market after they scaled up human moderation in west? That's what fair competition is - facebook, google et al blocking what PRC gov wants blocked and handing over info on dissident according to who PRC says are dissidents. All expensive things PRC platforms has to do. AKA "fair" competitive enironment. Thinking western platforms should compete in PRC without following PRC laws is insipid. Fair would also be the TikTok/Oracle JV where Oracle responsible for US interests, like PRC has for Microsoft. Nevermind half the reason western platforms were blocked was because they were unmoderated platforms that helped organize extremist attacks that caused 2009 minority riots. It's one thing to block TikTok if TikTok allowed 9/11 and refused to do anything about it, it's another when they do what every other US platform does, but just better.
We are trading partners for sure but the American model and Chinese model are fundamentally opposed. For the last 10-15 years, tensions have been getting hotter because Xi has been consolidating power and flexing his strength across the region and exporting censorship. You can look at Hong Kong as an example of this. It's clear China doesn't want to live under a Western hegemony and has been trying to get more power and the US sees this. Trump instituted tariffs and we've also banned Huawei 5G equipment and it's all in the interest of national security and China hasn't liked this. So things have been going back and forth. TikTok is just seen as a scary possibility in that they could influence American minds at a scale that is unprecedented. There's a law in the US that no foreign entity can own a large share of any US broadcasting company. This is just to prevent hostile takeovers and controlling media. This is pretty similar to that in that TikTok is a media company and the US wants to exert that same control. User data is a red herring and honestly the least of the concern if you think about the soft power they control with the TikTok algorithm. Even though we have a trading relationship, things have been heating up under the surface for decades.
Also, how is China an adversary? I thought the USA and China were trading partners.