Quality assurance is a big subject, and depending on the desired goal, there are several ways to do it. There is no universal right or wrong way.
Make / inspect / accept quality processes as practised in the past are unpopular today. Although initially cheap and simple to implement stuff gets through the net and the process becomes hideously expensive – too many people checking rather than producing. Characteristic of firms producing 'quality' goods that cost too much.
Instead, much better to build quality directly into the 'Make' phase, expensive at first but fully applied it can eliminate the need for inspectors entirely. The method involves looking closely at every aspect of the manufacturing process and carefully eliminating all sources of error. Skilled men are a major source of error; if they can be replaced by machines, it's done. Most of the time this system works well, and the cheapest way to fix occasional errors is to replace faulty items without fuss.
Quality depends on the market, not on the desires of elderly gentlefolk. The market for hobby lathes is tiny and it consists mainly of chaps who absolutely refuse to spend grown-up money on tools! (What many think of as serious money is actually chicken-feed.) Although quality is wanted, no-one is prepared to pay for it! So there's a market for stuff made down to a price and for second-hand tools where someone else paid big money in the past. It's our own fault. Machines would be much better made if we all started the hobby off by spending £10,000 to £20,000 on a new lathe.
Other markets are different. That for electronics is much larger, highly competitive, fashion conscious, and the technology is moving forward quickly. Last year's model is out of date, but it must work well because reputation matters when competition is red-hot and huge sums are involved. When products like mobile phones sell by the billion and then collect usage revenue, it's well worth driving prices down and quality up. Cars are also highly competitive, with large numbers of customers tending to push quality and features up and prices down. Good news for the consumer, but it does generate an unrealistic expectation that everything we buy can be both good and cheap.
Then there's White Goods. These are designed to last at least 5 years, but then become unreliable. While the customer might want a fridge to last a lifetime, how can the manufacturer stay in business? And there are good reasons why old fridges should be replaced, energy efficiency, CFCs, faults etc.
When modern industry finds it worthwhile, it easily outperforms anything done in the past. Even the recent past! Aerospace, computers, pharmaceuticals, maintenance, medical, etc all better. Unfortunately, the ordinary Joe doesn't get the best at low prices all the time unless the economics are favourable. It's an imperfect world…
Dave
PS I spent most of my life being unable to afford computers, new cars, lathes, and microscopes. SWMBO put top priority on house, food, holidays, children and cushions!