@tomcy6’s points about the compromises that are inherent in cost-efficient manufacturing are very salient. I have some experience of mass manufacturing quality control and know that it is (or at least it used to be many years ago) done through random sampling of the product at set intervals at various points throughout the production process and of the finished products. Not every item is inspected / tested to ensure it is within tolerance and defect free. The sampling rate is set to deliver the percentage of defect-free units the manufacturer or customer can tolerate (which in turn is dictated by the market - us!). Taking tomcy6’s 95% example, this would mean 5% maximum of the production can ship with a fault of some kind. That 5% limit might be relaxed for ‘minor’ defects and tightened for major ones. Obviously, for airplanes, spacecraft and the like, the only sample rate acceptable is 100%, 100% of the time. But for audio products it might be 1 in 20 for a contract mass manufacturer (say in Taiwan), increasing to 1 in 3 or 4 for a medium-sized producer in Europe or North America, right down to checking every single product at every stage for small-scale producers of really high-end gear.
I get it that audio equipment makers need to make a profit and are under the same competitive constraints as all manufacturers - especially in the budget to mid-level end of the market. But having to return / fix gear all the time is a hassle. I believe they can and should do better. And I’m not at all convinced that going further up market improves matters - just look at gregp858’s post about his new $25,000 KEF Blade Two speakers?