Today, those features are no longer necessary, and we look for other measures of quality in products -- for better or worse.
I grew up in a "midcentury modern" house, and my family lives in one today. I find the modern decor to be comforting because in my case it reminds me of home. My mom claimed that the sparse decor was easier to maintain, for instance: "There are no knick-knacks to dust around." Truth be told, the house also happened to be available during a very frothy market, and my spouse would have chosen something more traditional.
It's also claimed that the simpler decor works in smaller houses.
We were not rich. The MCM houses in my 'hood, including ours, are certainly not clutter free, yet still feel pleasant and comfortable.