We have flea markets. And you can find everything there. New or used, and mostly used. But there are no shops that are dedicated to selling used stuff.
Why ? It isn't one reason, Bingley
Generally speaking : if you scan any region of the world, you will find types of businesses and establishments that you will not find in other countries/regions. Societies are different. Globalization is melting corners of the world into one pot, but things aren't completely identical.
Regarding wealth, not everyone around here is wealthy. You get almost the same mix in the U.S., Europe, Asia , and about anywhere else. There are people (either low income, or used to thrifty lifestyle) who may buy used equipment (especially in business) or a used car ..etc. But, not personal items like clothes and such.
Regarding embarrassment, there are off course cultural differences. A few decades ago, we had many more American expatriates here (compared to more Asians now), and they held garage sales ..etc. I bought from them tools, books ..etc. But honestly, we were shocked to see them selling their underwear. This was a cultural shock. LOL.
This is what comes to mind right now regarding buying used stuff.
And off course, you will find all kinds of people in any society. I am the kind of practical, simplistic type of person , so I bought a used car before, and may go to flea market to find tools ..etc. and have bought a used desk from a closing company ..etc. But there are other people who will never go "cheap" like this.