I would say that many of those cheap goods are simply trash that people buy impulsively that either collects in their homes or ends up in landfills in a short period of time. Fast fashion being a well known one, where people buy lots of cheap clothes that are of poor quality and may only be worn once before being thrown out. We don't need these things and the environment doesn't need to be full of landfills of this junk either.
Maybe, but you're basically describing the entire US consumer culture. I'm originally from the UK, but moved to the US decades ago at age 25. The difference between the two cultures in terms of consumer behavior is huge. Companies like Black and Decker (tools) or Kitchen appliance manufactures make different products for these two markets to account for the different tastes - US consumers prefer semi-disposable quality products that are cheap vs UK preferring higher quality at a price. e.g. using metal vs plastic parts, etc.
Teenage fashion (e.g. Shein) is probably a poor example to focus on though since, even disregarding fast fashion, teenage clothes don't have a long usage period - they get outgrown or fashion changes, etc. The price/quality point of Shein is well suited for this.
