Because they're cheap. The majority of people don't care about quality as long as it's presented well and meets some fairly low benchmark level (whatever that is). Pretty much all industries have demonstrated this, and cars seem to be no exception.

Country of origin/ethics/politics also doesn't really play a part in purchasing for the majority of people (again, simply shown through sales)

Because people care about price and quality, if they're within what the person wants, where the car comes from couldn't matter less.

Same reason you would buy a China made computer, phone etc.

They are the new Japan.

"Made" or "designed"?

Our Tesla Model 3 was made in China…

They’re… Chinese people that buy locally?

Ignorance and no standards

Because it’s a nice car.

I get your sentiment though, feels hard to trust.

You comment recalled the moment when Elon Musk laughed off BYD years ago for me. You will be told why with hard data.

Quality is going to shit across the board, so short of being able to buy quality, at least why not buy the cheapest flavor of shit?