I still wear heels, but not high ones, I have a mix of slightly heeled boots and boot shoes, I wouldn't wear a court shoe style as I agree they are not so fashionable, and really really high heels aren't either. Lots of young people though try to get a bit of height/fashion out of very clumpy shoes, heeled/clump trainers and so on, especially if wearing flares.
This thread does remind me though of the many attempts over the past 10 years to convince everyone that skinnies were totally passe and that no young people ever wear skinnies, and that to look good we should all ditch them. Now, it's true that baggier jeans are in, my girls wear them, but the style they wear them in which is crop top, show stomach, baggy jeans, trainers is just not one that at my age I could begin to emulate. They also occasionally wear skinnies or slim style jeans if they want to wear very baggy tops.
I was on campus this week and this show off your stomach/baggy jean look looked amazing on some of the students, but I don't think that means that if middle-aged women started wearing crop tops/baggy jeans/trainers they would look fashionable, we just look our age wearing that clothing.
In other words, there isn't a magic shoe that signifies youth, and you just look your age wearing flats or trainers, perhaps even more so as they can make a shorter person look a bit dumpy and if you have a matronly busom/not much of a waist, you look older. That's just my opinion of course.
The one place I've noticed that many students wear heels is for graduation. I've often seen them tottering across the stage, it's really noticeable. So there seem to be certain types of events that are still associated with heels, weddings probably the same.
Not all flats are healthier of course anyway, ballet flats provide no support for feet. Trainers can go sweaty/soggy although you can waterproof them. Flat sandals tear up my feet in summer. A bit of a heel isn't necessarily particularly bad for your foot. Wearing enclosed shoes made of plastic is also really horrid, and so many shoes are plastic now and not leather, they are really uncomfortable, and plastic heels are the worst.