Both. China is where most consumer tech comes from, and the rest often includes parts from China as well. Taiwan has TSMC which makes all the big CPUs, but honestly all the small stuff like consumer electronics comes mostly out of China. If they did want to integrate some sort of spying they would have the opportunity, and in the past individual threats to the state of many countries have had supply chain attacks carried out, so it is not an unfounded fear.

That all said, China is run by the CCP, an ostensibly Communist party, so red scare, not to mention Chinese, so racism, and Party, because Americans are against fun, or at least in government they seem to be. China also has an abysmal record on human rights, though coming from anyone in the west criticism is somewhat hypocritical given prison labour, proping up dictatorships, coups, exploiting slave labour, and so on. Nobody is doing a perfect job, nobody is saintly, but there are fair and unfair criticisms against China as a nation state and those do inform some of the fear of their potential for spying.

Now TikTok, Reddit, Meta, etc... There are the really scary tools with far too little attention.