Most people buy cheap stuff, I think there are three main factors that cause this. 1. It's what's available in big box stores, 2. It's cheap (affordable), and 3. Many people don't have the skills/space to build their own.
Personally I am quite lucky, having learned woodworking from a very talented shop teacher in high-school, I am more than capable of building my own furniture. One of my first projects was an end-table with a chessboard built into the top with a few decorative inlays, all cherry and maple. When I built it, I put maybe $20 extra (nearly a decade ago, forgive my memory) worth of support boards, the table is one of the most solid things I've ever personally see, and was capable of supporting 3 ~150lb people standing on it (yes, it was fun to test this). I remember having to beg my mom to purchase the wood, and the total was under $200, ballpark $150 I think, not including labor of course. I fully expect it to last well past my own life, and it will be a great hand-me-down to my kids.
Contrast this to a nice looking bookshelf I picked up from Ikea two years ago that had felt somewhat sturdy in the store, the shelves themselves were made of real(!) softwoods. It was $130, which felt extremely cheap, but worth a shot. The thing lasted 6 months, then summer came, with it's humidity, and the thing collapsed. Turns out having correctly designed supports is pretty important, who would've thought, certainty not a multi-billion dollar furniture company. So, for having to spend 3 hours assembling it myself, I got to watch it implode when the weather turned, lovely! The sad reality is that this is the standard for household goods in many American homes.
The experience of buying that utter garbage bookshelf prompted me to start building a workshop of my own and to start woodworking again. I had gotten a burning desire to build high quality and long lasting products for people. I've been working on small projects when time permits, mostly drink coasters and cutting boards so far, but I'm actively planning out bigger pieces of furniture as future projects. I've given a couple items away as gifts, and even made a few sales over on etsy[0]. Compared to writing software, which is lucky if it lives for more than few years, I've gotten a massive sense of satisfaction in knowing that for each product I build, it has a good shot at completely outliving the owner.
[0] https://www.etsy.com/shop/MyceliaDesigns