Because big companies make lots of profits from it, I imagine.
> Its going to continue to bite us and everyone in the butt.
Yes, unless we change our ways.
Large multinational corporations would love to shift production to Vietnam, Thailand, Indonesia or India, where labor is now cheaper than China, but there are logistics obstacles. Apple now manufactures some phones in India, but mostly older models.
Software is eating the world, as Marc Andreessen says. So who controls the software -- including by controlling the hardware the software runs on -- controls the world.
This means that every polity that wants to be truly independent needs to control its computing infrastructure, ideally all the layers of the technology stack from chips to social media. So it would be well worth polities such as the USA or EU putting up whatever level of import tariffs (and other measures) it takes to encourage manufacturers to do these things domestically.
Not that doing so would be that much more expensive anyway. The cost of low-level assembly line labour per iPhone is probably only a few dollars. I'd guess that building them in the USA would only add $10-20 to the cost.
You're right about this, including with backdoors. Electronics from China must be treated as treacherous computing devices that obey the orders of the Chinese Communist Party.
If the West was sensible, we simply wouldn't buy any electronics from them.