the structural disadvantages that the article points to, long iteration times, weird inside baseball materials science and tacit knowledge in manufacturing are real but the author is wrong to dismiss the scale.

Scale doesn't help them much in getting the engines up to quality but it does give them the ability to run dozens of experiments and companies at the same time. And they only need to have a handful of breakthroughs once.

That's a pattern that's already repeated it a few times, China has had trouble catching up in the car market for a long time, on semiconductors. On the first they're now on their way to capture the market, on chips they're catching up, and on military engines you can already see the gap closing. I predict the title of the post will age badly, within 5-10 years there'll be competitive commercial planes in China.