SINAD will not show other behaviours or even outright broken elements in design. It only describes the operating range without noise or distortion.
There was a time after WWII, during the economic reconstruction led by the Allies (for their purposes), when Japanese manufacturing was synonymous with cheap mass-produced junk. The direction that eventually took goes without saying. But the outsourcing that for the last handful of decades represented the relationship with the Chinese will, and is, giving way to their efforts to establish their autonomous expertise and quality.
While SINAD won't show "broken elements" in design (whatever that means, as it could mean anything from broken hardware design where you have pisspoor heatsinks, or just grounding blunders, OR simply catastrophic software-side failures). I still feel pretty safe raising the request for showing blue-tier devices that suffer such examples of being broken while holding on to blue-tier SINAD metrics. Again, I'm not saying it's impossible, I just haven't been exposed to any to then turn around and hold firm to the statement of almost saying something like "Yeahhhh, SINAD don't mean much".
As for the whole history of Chinese goods being as badly perceived as older Japanese goods of the WW2 era. I said when I was in highschool that China could beat us in overall production capacity mixed in with quality - per dollar if we simply were willing to pay for such.
And boy does the Matrix Audio line of devices demonstrate and verify these sentiments I held.
On the outside, I see shoddy Chinese quality as a byproduct of demand, and of a nation in rapid uptick. Sure they probably don't have 100% of the sophistication it takes to be in the watch industry what Swiss mechanical watchmakers are. But boy are they catching up at a rapid pace.