"Locally made" makes it sounds like they're bringing them home from the farmer's market in a canvas bag.

Glad to see Comac planes being used at production scale. Hopefully they are safe and push Boeing to do better, but based on recent US actions I bet they will ban Comac to prevent competition.

Locally produced, artisanal airplanes.

Boeing has generally been one of the lynchpins of China-US trade relationship, and with both the current geopolitical climate and the ongoing quality issues of Boeing aircrafts, of course the Chinese airlines would want to hedge their bets and take a risk on domestically produced jets, even if it is new and relatively unproven at this point. It doesn't mean that they will stop buying from Airbus or Boeing completely, though.

The C919 uses many American/European produced components/subsystem, most notably the CFM LEAP engines, which is also used by both Airbus and Boeing.

There is more that goes into an airplane than the people maintaining or assembling it, which can and does go afoul. There is the entire manufacturing process, how materials are sourced, processed, refined, machined/formed, heat treated, stress relieved, coated/plated, assembled, and the list goes on. That is a major factor why aircraft are so safe and if you think China's material and process controls are as rigorous as someone like Boeing or Airbus, it isn't. It has taken decades of actual aircraft manufacturing to get the formula right for those respective companies and they continue to evolve as time goes on and new information is learned.