I've got a bit of experience working with subcontract manufacturers of varying sizes, both here in the UK, and in the far east (China and Taiwan).
Uk
I've worked with a few places in the uk, ranging from very small (one pick & place machine, mostly women sat with soldering irons placing components manually). Think small industrial estate unit, bit of a dump inside and quality very variable (in a previous job, they built stuff we didn't have capacity for in house). Through to a bigger much more professional company in my current job. We tend to use these for low volume stuff and quick turnaround prototype runs. They're very capable (most of our stuff is down at 0402 size), and quality is good. Their shop floor is smaller than that shown in the video from Dave, and they only have the one line but other than that pretty much the same sort of stuff. I don't think they have any automated test though.
China
We initially produced some of our products with a Taiwanese company who did the manufacturing in China. They had some impressive equipment (Fuji pick & place stuff, not sure about the rest). Workers were mostly low skilled, but they did have some on site R&D and their staff were very helpful. I visited them in Tianjin 4 times over a few years, mostly to commission our test solution and each time they were very welcoming. We had in place a good manufacturing contract which I think was key to ensuring there was no random swapping of components for cheaper alternatives, and our operations team were always on top of any QA issues. ESD precautions were in place and always adhered to when I was there, but I don't think they had an ESD floor.
Taiwan
We later moved to a Taiwanese manufacturer who do the manufacturing in Taiwan and their facility is in a different league to the one shown in the video. The facility is massive! I got a tour of the SMT line used to produce our product which was entirely located in a clean room with proper ESD floor. Bunny suits required for all workers, sticky pads on the floor to clean dust off your feet and an air shower on entry. From what I remember they had Hitachi equipment capable of 01005, auto optical inspection after component placement but before reflow (the boards have cans fitted so inspection required before placing the can and reflow soldering the whole thing). They had ovens to bake components before placement, encapsulation molding machines (more on this later), laser markers, 2D barcodes on everything for full tracking, and even a metal sputtering machine.
Once populated, the individual boards were de-panelized with a dicing saw, similar to those used for separating semiconductor die from a wafer.
They were able to make some quite advanced products such as tiny RF modules (bluetooth, GPS etc). I was shown an example of one module they produced the size of a QFN56 which for all extents & purposes looked like an IC once complete. In reality it consisted of a multilayer substrate (mega thin multilayer pcb) on which were placed and wirebonded multiple IC die (micro, flash & radio), a number of passives (about 12 in the example I was shown), and a crystal. They then used the package molding machine to encapsulate everything and the metal sputtering machine to coat the outside of the encapsulation in thin layers of copper & stainless steel I think. This served as the screening can. I think they said they could do RF stuff up to about 60GHz.
Working with them has been an absolute pleasure. All the staff I dealt with both remotely via email and in person (been there 3 times now to their facility near Taichung), have been superb and very competent. They really are experts at what they do and their capabilities world class. They were also incredibly courteous and ensured I was led out of the building quickly when an earthquake struck while I was sat working on our test system which was much appreciated!
So, its easy to tar the far east with a bad reputation if your experience is with the tiny sweat shops, but there are companies out there that could definitely teach those in the west a thing or too.