I will never understand how this trend started in the first place. If you look at e.g. digital cameras, they all have touch screens these days, but they also still have buttons and dials everywhere. The one in front of me has eight physical buttons, seven dials and a power switch. The reason is obvious: when you're taking photos, you don't want to be looking down at a screen; you want to be focused on the task at han…
Digital cameras are increasingly a niche product that exist mainly to cater to people who specifically want a the "SLR" user experience. If you just want to take decent enough photos, your smartphone's camera today is better than most prosumer DSLRs from like five years ago.
I don't think today's DSLRs have the form factor that they have because it's objectively more usable. It's just the form factor that their self-selected customers want. One piece of evidence in favor of that is that all DSLRs do have big LCD screens on the back and often require a lot of menu diving to access any functionality that didn't exist in cameras before the digital revolution.
There's still a physical dial for switching modes even though that's not something you actually change that often. Meanwhile you often have to dig into a menu or go through crappy buttons to do things like delete a photo.
I won't go so far as to describe it as fetishization, because I think that's unfairly critical. But I do think a camera UX designed from first principles purely for usability would not have the same physical controls as a typical DSLR.