Military Y20 reached 80+ now within a few years - they have indigenous tech to apply to domestic wide body, and can scale up production of large aircrafts if they want. But taking 929 slow because civilian aviation is _harder_ than space, more international requirements etc, why C919+929 needs to use foreign components for easier certification. The global economics justify it, the regulation/geopolitics makes it hard but they're diligently pursing it.
But economics also don't CLEARLY justify domestic wide body when they can focus on electrified HSR without fossil inputs, AND PRC pop density / geographic concentration limits future of civilian air due to air corridor congestion.
I expect PRC to mass produce domestic F9 if the economics clearly justify it. LM5 already estimated at F9 $3000 per kg, so hard to say how much mass producing PRC F9 tier reusable can drive down cost + add capability. If it's there's clear significant demand for more than sustaining mega contestallations past 2035s, I'd expect them to spam F9 for domestic use, before civil wide body that's going to take longer due politics of international aviation.
The economics clearly justify mass production of widebody aircraft, yet China is unable to produce their own.
And you expect China to mass produce Falcon 9 rockets? How about they start with a simple airplane first.