99% of the “going in or out of style” in home decor or fashion is generated by the industry to churn sales. Same in Wall Street where the big brokerages pump out alternative fear or greed to churn portfolios and generate commissions.
I am sure that is part of it, but some styles just don’t stand the test of time, while others are timeless. It’s the same with fashion. When it comes to popcorn ceilings and sag carpeting, I honestly think it’s mostly a “clean” issue. Both get really really nasty over time in most places.
Have I seen a few well maintained homes that looks fine with both? Yes! and it’s sort of shocking, because it can catch you off guard to see a new “clean” version of it. Because it usually looks like a asthma starter kit.