China

It's a difficult subject. Some unorganized thoughts:

• What is being done in Xinjiang and Hong Kong is abhorrent, as is repression elsewhere in China. Actions taken or threatened abroad are also worrying, including the claimed right to invade and annex Taiwan by force.
• China (or more properly the ruling CCP) is not unique in history nor even in the world today for the immorality of its actions and China has itself been a victim of other powerful nations; however, none of this is an excuse, least of all for genocide.
• From Tibet to Tiananmen people elsewhere in the world have always had reservations about China but until recently it was believed they were liberalizing. Generally it was hoped that trade and contact with the West, and even the integration of a semi-democratic Hong Kong, would help with this.
• The ongoing protests in Hong Kong and the information coming out of Xinjiang is making people across the world (or, as much as I can say, at least in the English speaking West) reconsider their relationship with China.
• It's fair to ask if the West should have engaged economically with China as it did decades ago, or if in retrospect that enabled a despotic regime that is now a superpower engaging in wide-scale human rights abuses. While useful in a certain sense I don't think guessing about counterfactuals can give us a clear path about what to do now. (It's also far from guaranteed that a different approach would have been better: isolation and hostility on the part of the West might have pushed the CCP in a direction more similar to North Korea.)
• Individual choice about what products we buy won't have a direct impact but it could be impactful if companies start finding it's a PR hit to deal with China.
• The more a country trades with China the more dependent on China they are, and the more influence China has.
• Corporations are similarly affected and China will use this to their advantage, e.g. erasing mention of Taiwan as an independent country on airline websites, or American cultural products (ESPN and DreamWorks, to name a few) showing maps of China that include extensive and unrecognized foreign claims.
• I think it's wishful thinking on the part of the article that trade with China is mostly something that benefits the 1% and mostly hurts everyone else, and therefore could be stopped with little consequence to most people. It's not like China is just the Walmart of the world and we could choose to shop elsewhere even if it's a bit more expensive or inconvenient—China is the most important part of the global supply chain and replacing its role from mining to manufacturing would be a multi-year process. (In a way this is happening: manufacturing in China is getting more expensive and is moving to other countries and China is accordingly trying to shift the focus of its economy.) China is also a major importer with 13.6% of the world's share of "merchandise imports" and economies across the world depend on selling goods to China.
• China is also integrated into the world economy in other ways such as Chinese ownership or partnerships with foreign companies and the Belt and Road Initiative.
• I don't know what the effect of disengagement and sanctions would be. There's a hope that the threat of such actions could influence CCP policy. However, after the "century of humiliation" of China being taken advantage of by world powers (western imperial powers and Japan) they could be uniquely hostile to giving in to external pressure on what they consider "internal" matters.
• There are 1.4 billion people in China and most of them are completely innocent of any wrongdoing (at least as much as the average American is innocent of the Iraq invasion—or even more so, since it's not like Chinese citizens can elect their leaders) and they are just normal people the same as people anywhere else in the world. They are as deserving of stability and security as much as anyone else and actions that risk toppling the CCP regime (such as protracted economic warfare) could have profoundly negative effects on them. It's easy to sit in comfort on the other side of the world and callously dismiss the lives and wishes and hopes and dreams of more than a billion people, to say that the risks they would face in the potential turmoil of the CCP's collapse is a price that should be paid.
• There is no guarantee that political change in China, including removing the CCP from power, would be violently or chaotically destructive: neighbouring South Korea and Taiwan transitioned from dictatorships to prosperous democracies with relatively little violence.
• There is no guarantee that a free and democratic China would respect human rights or be less bellicose.
• Military intervention to stop the genocide in Xinjiang is unthinkable, impossible, and unethical—a war of that scale would be too destructive and create too many new victims.
• It feels like the world is at risk of bifurcating with countries being pulled into American or Chinese dominated blocs with fewer trade or cultural connections between them.
• Conflict between super powers is not inevitable. The "Thucydides Trap" is not destiny.
• China's continued rise is not inevitable: they have an aging and shrinking population and it's unknown how well their plan to deal with manufacturing moving to cheaper nations will work out. It's uncertain how well the CCP could survive a downturn in the Chinese economy—so far it's been easy for many Chinese to accept the CCP's actions as necessary for prosperity.
• The continued role of the US in global politics is also not inevitable. Certainly the political and business/finance establishments will try to will it so, but the American electorate and culture are in an unusual place right now, to say the least.
• Climate change is a real wildcard for what could happen: "Research has shown that beyond a certain threshold of temperature and humidity, a person cannot survive unprotected in the open for extended periods... China’s most populous and agriculturally important region could face such deadly conditions repeatedly..." (Personally, I think as a last resort before such a scenario plays out China would try unilateral large-scale geoengineering. In circumstances like that, who could blame them?)
• It's worrying what effects enmity with China (including seeing them as a "new Nazi Germany") could have on Chinese people living outside of China (immigrants or their descendents) or even just people who could be mistaken for Chinese. Hatred, bigotry, and discrimination could become much more prevalent against these groups and divisions and mistrust within our societies could deepen.
• It feels like things could get much worse and I don't know what the solution is or what would help, whether at an individual level or a policy level.
• The possibility of any number of terrible things happening is not a reason to lose hope or to give up. Even if we don't know what could be done we can at least be on the lookout for small actions or kindnesses we could do that would help us better understand and get along with each other on a personal scale.