Taipei, Taiwan has something
similar. The video doesn't do it justice. The upper floors get into the specialty stuff (and they have everything!) Additionally there are hundreds of stores outside, again selling everything electronic. I pick up used 2 or 3 year old iphone there every few years for a hundred bucks US.
I used to stay in Huaqangbeilu for many years.. my hotel was 5 minutes walking.
I shopped at SEG market (Chinese pronounce Saigo.. like Cairo). In the video, the first floor is all electronic components and tools. Virtually everything. The second floor is all about electronic devices and modules, high tech devices, rf xceivers, smart screens, android devices, etc. The third floor is all computers and computer products.. you can either buy one or they build it for you while you wsit..4th, fifth and up are companies selling everything.
You can't ask for anything and a chinese seller tells you he doesn't have it. Ask a mobile phone seller you want cheeseburger, he would tell you wait! runs to a nearby McDonald's and get you the food.. he makes 50 cents.. not bad. Can they be more practical.. if the end goal is money.