My impression of the design world is that new stuff shows up when people are "bored" with something, and they can easily get bored when that something is popular/everywhere.
It doesn't have to be a kitchen, it can be home decor, home colors, clothes, cars anything.
In fact, I'm told, that there's some sort of consortium that meets every year or two to decide "what colors" will be "in fashion" next. As opposed to letting people choose colors and see what floats to the top of the popular list.
So, in a very rough description, for kitchens, it goes more or less like this: some rich person or a group of them, choose an expensive "luxury" item. Then one of them ends up with their home completely documented on one of the magazines, then more people end up buying it, then more magazines, tv shows and websites start publishing more and more about it, then high-middle class people start using the items to "make their homes higher end", then the price falls because manufacturing increases, then the middle class starts seeing it everywhere and buying it. At that point, the upper classes think it's a trend and already outdated, because "everyone" can have it.
A few years after that, when all the new-home builders have put the item in nearly every home, people will be sick and tired of it and a new thing will take its place. You can expect that any second now, people will look at brand new kitchens with "farmhouse" sinks and say it's an "outdated 2000's home" or "outdated 2010's home" depending on how rich the person is and/or was paying attention to such things.
I'm waiting for stainless-steel everything to disappear again for another 20-30 years, due to how popular it is right now. I don't mind stainless steel, but I tend to prefer white appliances anyway, it's easier to replace just the appliance that broke down/needs it anyway, instead of the entire kitchen.
Also, please pay attention to how much popularity makes people change opinions. A few decades ago, a "built-in" appliance, like a dishwasher or fridge, was considered "hidden" and people thought that the feature would "make the kitchen larger" -- I remember when people with such appliances had to tell visitors where the appliances were. I never fully understood that -- it was more than clear where the refrigerator and dishwasher were, even if they were "fully integrated" because every single one of them broke the lines of cabinets with their particular "features" that would let people open them and/or ventilation happen. Nowadays, people are *so* used to appliances like that that they locate them themselves with no help whatsoever, even though fridges, for example, got even stealthier than they used to be, today even the ventilation grid seems to have been eliminated, and they *still* can be easily located.
I happen to *also* think that there are things I do *not* want to hide from my guests and want them to locate them by themselves *immediately* and without having to ask for assistance, and that includes the sink, the stovetop and oven, the dishwasher, the fridge/freezer, the light switches and the toilet. (Yes, "the toilet" is here because about 10-15 years ago, when reading a magazine about homes, I was astounded to find out that some misguided people thought it was a good idea to pay over US $10,000 for a toilet that had some model name along the lines of "hat box" and I asked around if anyone would like to spend any time during a time of need trying to locate a toilet that looked like that or trying to guess how to open/operate the damned thing, and no one volunteered, and *everyone* thought I was kidding when I then informed them of the price tag for the "privilege". Needless to say, I don't think that style of toilet has caught on.)
There is no need to say that those are my personal opinions and they don't even get you a cup of coffee or a subway ride. I do suspect that my point of view is very popular and shared with most people, but it's not "chic" to agree with it, we should all try to imitate the rich and famous instead. So we all end up with the same kitchen of whoever is popular this week. I'm told that currently, that would be Barefoot Contessa's Ina Garten, whose kitchen won some kind of prize and a copy of it is visited by thousands of people per month -- the copy is in a park in NYC, I believe.
