That said, watching the Comac C919 shitshow (14 years and still not in revenue service, and this is for a 737/A320 clone), I'm not holding my breath.

This is true, but this is also a command economy. They can do that for a long time. At least 10 more years with gov't support. They'll get there eventually, plus the order book is essentially infinitely large because gov't will immediately force all domestic carriers to cancel foreign orders and only buy Comac C919. I am guessing it can handle 100% of internal flights (size / distance / etc.)

It's too bad Mitsubishi has basically given up too. It'd be nice to see more competition to Boeing/Airbus, especially after the 737MAX debacle. I'd have a lot more trust in a Japanese-built aircraft than a new Boeing, and I'm sure many others would too.

The C919 and C929 both fly with western avionics and jet engines, so they aren’t really that far off from airbus and Boeing, and don’t really bring anything new to the table beyond more competition from China in putting everything together.

They're building their own engine as well: https://en.wikipedia.org/wiki/ACAE_CJ-1000A

I agree that the C919/929 pose no threat as is, but the Chinese are clearly playing the long game here and their massive domestic market coupled with government arm-twisting lets them scale: the C919 has already racked up over 1000 orders.

China is still at least 20 years behind on jet turbines. They can get the power or economy (in terms of use time/overhaul), but not both at the same time. Jet turbines are hard to reverse engineer, and you really just have to put the time in on materials engineering.

Probably the Chinese will have to rely on some derivative of the Russian PD-14 engine. It is very probable that the chinese will lose access to western engines due to sanctions in the not so remote future, and their indigenous projects are still very far behind the state of art in jet engines.