Yes, using imported equipment, tools, labour, QA, know how and management staff. They just rubber stamp the made in China seal. And data supports that claim since it's Taiwan the world producer of 7nm chips.
Yes. I understand your logic. But Truth and Facts are two different things.
We have no evidence that China has actual real capacity to mass produce those phones for mass demand.
As other comments say, it may well be chips that were manufactured before sanctions, or chips manufactured on low scale.
The second point is why Global Foundries dropped the chip race, and why TSMC is the global leader.
And under sanctions, I see no reason why China would suddenly become better at mass production than TSMC.
China has a long tradition of inneficiently throwing money at things, so their chips may also be on a very low yield wafers and heavily subsidized. That's not sustainable either
The article is based on an analysis of a Canadian firm that bought the phone on the open market, tore it down, and confirmed the chips were made by SMIC.
There is no reason why China needs to be better at mass production than TSMC. They just need to be able to do it, because they can't reliably buy chips from TSMC anymore. The evidence is overwhelming that yes they can do it.
Without competition from TSMC the price merely has to be reasonable, not competitive, so I don't see why they would go the GloFo route either.