Cold War era Soviet designed/built airliners shares the same philosophy as that of combat aircrafts: focus on a main purpose and pretty much ignore or paid little attention to everything else.
The result is that Soviet airliners earned their reputation of being of lower quality in everything that would make a desirable human transport. Besides, there was the psychology involved in that Soviet airliners were designed in mind with being quickly turned into military transport if necessary. That mindset affected how the aircrafts were initially conceptualized.
Perception is fickle, I will grant you that. However, you should also understand that perception has many owners and that is where it gets dangerous for the seller. The aircraft maybe structurally more robust than required and functionally just as capable as its competitors, but if other qualities, such as noise and comfort, are ignored or minimized, no amount of PR campaign can save the aircraft.
If the Chinese government make captive the entirety of internal air traffic to only Chinese airliners, there is no telling if the Chinese government will use trade pressure on other countries, particularly developing countries that do not have as stringent air travel guidelines as the Western market, to support the sale of Chinese airliners.
However, I doubt that this 'worst case' scenario will occur. The Chinese are more conscious of 'face' than the Soviets/Russians do. The Chinese economy is not as closed a system as that of the Russian and its smaller Soviet bloc economies. As such, the Chinese product will be closely scrutinized especially when the Chinese designers/builders are willing to subject their products to all Western standards on what make an acceptable aircraft.
Here is a readable article on how a new aircraft is tested...
https://www.wired.com/2017/03/boeings-test-protocol-new-planes-beat-oblivion/
Here is a relevant note...
The Chinese airliner will
NOT get that latitude. Unless the Chinese government successfully bribed all the Western testing officials involved, the Chinese airliner will undergo full inspection and testing. Five thousand hrs is a lot of flying and it must be thru all the common environment like the tropic to the desert. Qualifying a new aircraft is always a money losing period. The Chinese cannot afford to field test an inferior competitor.
