I would say the big makers of guitars had real issues in the seventies, but today you can get really good instruments for relatively small prices.
CNC machines along with a consumer QC expectation (who are not hesitant to return what they consider a defective item) has been my experience. I don't prefer to buy an instrument on-line, but with today's exceptional return policies it's not a gamble, anymore.
World Musical Instruments, CorTec (and others) have mass production and quality down to a science, and at a very low price point. Indonesian PRS guitars are lovely... Ibanez, Schecter, et al. QC of Chinese Epiphones, which were until recently fairly inexpensive (but now tip the scale at a thousand dollars or more--maybe inflation?) is impressive. At the 'high end' you find guitar's from Beijing's (violin maker) Eastman, sending out hand made custom shop tier instruments. The last several years have been a great time to shop for inexpensive to higher end guitars.
I don't think this translates very well to buying a DAC or headphone amp from Asia. Anecdote: last year my new Epiphone SG Standard had a slight neck-headstock crack (at the nut). It probably should have been caught at the factory, but it was hairline. I called Nashville, and was sent a replacement in a two weeks (they were out of stock so I had to wait that long). If I'd have noticed it when it first arrived (I let it sit around a month before I opened the box--not smart on my part) the on-line retailer would have sent me a new one, then and there.
However, with one of the little Chinese wunderkinds you read about here on ASR, I don't think after sale support/exchange is going to be as easy as buying a guitar, on-line.
I don't remember seeing the kind of pressing/handling defects that I am seeing now (and none of my old records show evidence of those types of issues, outside of sleeve scuff marks).....although, admittedly, I wasn't paying as close attention to record quality in those days.
If you rummage the the pages of
Audio,
Stereo Review,
Hi Fi, and early
Stereophiles from the late '50s and '60s, there were a lot of complaints about record quality. One thing I'll give Harry Pearson credit for... his push for decent quality records. Product from the '80s might have been the worst. I've heard it attributed to the 'oil crisis'.
The beginning of a real push for decent records was cottage industry labels like Sheffield (direct to disc), and on a mass market scale, Teldec DMM pressings. I've read negative comments about DMM, but I have them in my collection and have not experienced any sonic horrors. Japanese import pressings (supposedly using JVC 'supervinyl') were popular. MFSL half speed mastering. 45 rpm and such. Boutique high end hi-fi stores carried the audiophile product in my area. One of my most 'dynamic' records is an Umbrella label direct disk (distributed by Audio-Technica). Big band jazz... Rob McConnell... not a Count Basie tier performance for sure, but notable for how carefully it was recorded, cut and pressed (if not its artistic value).
Realistically, at the end of the day we're talking records. A certain level of imperfection is expected, and can be considered a 'feature'. The big question for record buyers is: if you have a record with only one major pop or click per side, would you rather have it at the very beginning of the record, or at the very end? My vote is at the beginning!