China can comfortably make chips that might be the equivalent of 5 year old Taiwanese ones. Last time I checked, that’s extremely viable.
No military general ever is going to say, “we can’t invade, we’re half a decade behind!”
Nothing screams “favorable market conditions” like WW3 and sanctions rivaling Russia.
But it would be incredibly stupid strategically.
I think only sensible path is to give Taiwan nuclear weapons. It removes all the dangers for ever.
End result requires more energy, has lower yield and is overall more expensive.
For military purposes and whatnot that's enough, but they can't put this in consumer devices without subsidies.
It is still hard to get much of a clear picture on how well they are doing on this stuff. Chinese companies are saying they are near parity, the opposition says they are 15 years behind, the reality is probably somewhere in between.
While they have made a lot of quick progress, that is no guarantee for future gains.
On the flipside Canon's Nanoimprint Lithography promises lower cost, even if their feature size is 15nm in practice. They also appear to be having competition now:
https://www.zyvexlabs.com/apm/atomically-precise-nano-imprin...
Recently Canon shipped the first commercial device and it appears that this path will see continued development. 15nm(14 advertised) is already good enough for, say, automotive applications.