It's really interesting to read through this thread, and I have to admit there's a lot of truth here. For me it's not "dead" because I've just started with overlanding / car-camping, and we as a family are really enjoying it.
I envy you guys in the US for the freedom to travel and camp in the most remote places. For us in Europe that's mostly not possible with kids and a tent — not unless you want to wild camp.
I do see and agree with the point that the term "overlanding" is extremely commercialized. Search for overlanding online and you'll find thousands of images of heavily modified, expensive 4x4s. That's what the marketing teams want you to believe overlanding is. Truth be told, I jumped on the bandwagon too and equipped our LC with light bars, a roof rack, fridge, shovel, water tank, kitchen box, ARB recovery boards and so on. But all that gear is stuff we actually need for off-roading and self-sufficient camping. There's nothing fancy about our separation toilet — we just use it.
On the other hand, whenever I see another G-Wagon on the Autobahn I think: that one will probably never see a dirt road. And the irony is that the G was built for it decades ago — a serious off-roader. But most of the ones you see now are bone stock and polished, owned by people who'd cry the moment a branch scratched that paint. The capability is all there; it just gets used as a status symbol instead.
You can tell when you see a true overlander, and you can tell when someone's just pretending. So yes, there's a lot of hype right now, partly because it's still a relatively new thing in Europe — but there's also a solid base here for the decades to come.
All in all, my take is that overlanding isn't dead. Only the hype around it will fade. And what I value most is the great community behind it all: people helping each other, connecting, and organizing trips together.
Cheers
Sebastian