> It's a market response where everyone needs to (or feels the need to) pick up and move at a moment's notice.

Yes, but it's deeper than that. Two broad reasons, though your point here is a good one.

1. We don't, particularly in the west, have the skills, shops/craftsmen, or access to resources to make things like we used to. It's a positive network effect where prices go up, folks don't do the work anymore, and so prices go up, and things get more unaffordable, and so forth until there's only a handful of folks anywhere that can build the furniture, decor, or houses that you allude to. Companies can't make this stuff and as they chase never ending globalized supply chains and increasingly fewer commodities or natural resources they market and sell plainer and plainer things - modernist styles and modernist architecture. With so many people in the world competing for the same products and resources, it's incredibly expensive to build anything "real" or with much detail or thought. So companies just cheap out and create surrogate products which nobody is ever happy with.

2. The changes we see in style can be attributed to changes in politics and civilization. Who we are and what we think of ourselves. It's bad or even politically dangerous to build ornate buildings or purchase expensive or ornate pieces for your home. How could you build a beautiful building when there are people starving?!?! (you see a version of this with rocket companies - how can Jeff Bezos spend his money launching rockets when Social Security is underfunded!!?!?)

Any sufficiently famous building or person who liked nice shit was a "colonizer" and "bad person" in some form or because of some argument and then of course over time folks just hide their wealth (stealth wealth, millionaire next door) and we pride ourselves on appearing poor, acting poor, and naturally, we create poor civilizations without much to aspire to. When was the last time you wore a suit and tie? Better yet, who in your town can even make a suit? Who is going to die for strip malls and parking lots? Who wants to invest in their neighborhood when you know instinctively it's just a house and it's not something you will really pass down to your children (they will just sell that suburban home you have). Americans in particular spend thousands annually to travel to countries in Europe for example, and to visit their gardens and nice buildings, which themselves are vestiges of an age when western civilization aspired to more, and why do they only do that instead of investing in their own gardens and making their own nice places for people to visit? We do this of course to some extent - it's big country after all, but those who understand this and why it's important are fewer and further between.