Here's a bit of interesting info I learned from an older gentleman who used to work on my watches in my town. He passed a few years back in his late 90s and had been a jeweler and watch smith for most of his life as a career then kept it up as a hobby after he retired, which is how I met him. This is his perspective so take it for what it's worth...
Back in the last part of the 1800s and into the first part of the 1900s, Swiss watches weren't considered to be very good. The US had the leading watch industry in the world at the time which lasted into the 1950s and Swiss watches were actually looked down on until just prior to World War II.
Why? It had a lot to do with industrialization and how they were made. In the US, a typical watch factory made nearly every piece of the watch literally "under one roof". The Swiss, at that time however, had lots of individual parts made by individual craftsmen over the long winter, usually at home in small shops. In the spring everything was shipped back to a factory to be assembled into watches.
The problem was consistency, or what we know of today as Quality Control. With so many different craftsmen and so many different shops spread out all over Switzerland where communications was slow at best, when all of the parts were finally gathered it took an expert watchmaker to literally hand-fit the parts together, adjusting each as needed to make a watch. Meanwhile back in the US factories, consistency was closely monitored and communications were quick and easy so variances were much smaller and more quickly found.
This was an issue mostly noted by professional jewelers and watchsmiths of the day (like the gentleman I mentioned earlier). If your watch broke and it was Made in the USA, your jeweler would have no problem ordering a part that would fit and installing it without a lot of work. If you had a Swiss watch, however, the parts were not only much harder to get but because of the variances found in them from so many different workshops each one had to be hand-fitted and custom adjusted - which took a lot more work and time.
But since the Swiss embraced the "American Way" of making watches in the early 20th century and the US (as well as the British, French and German) watch industry literally collapsed in the 1960/70s due to cheap labor overseas, the Swiss were literally the only ones left standing now making high-quality, high-precision watches.
