So on my seven year old Nikon D3s I can use buttons to focus and change the shutter speed, aperture, ISO, WB, focusing mode and focus selection point all the while keeping my eye to the viewfinder. I would almost never look at the rear screen except to check the always-on histogram if the lighting radically changed. This means I can react instantly during a sequence of shots without even thinking about the menu system. It is not just 'what I want' but a massive amount of directly accessible usability and configurability. Going into the menu system would almost never be necessary during a typical shoot.
The D850 I recently upgraded to is pretty much the same. I use the live-view screen on the D850 when shooting video but use the viewfinder and buttons (as above) when shooting stills.
And, to the original point of the discussion, these cameras also have lots of physical buttons and dials which are nice to have when they're properly designed.
Sure, and you could do that with an SLR from the 90s too, as I recall.
Camera manufacturers are very innovative when it comes to capabilities and new features, but incredibly conservative when it comes to user experience and form factor.
> they also still have buttons and dials everywhere. ... The reason is obvious: when you're taking photos, you don't want to be looking down at a screen
I agree that physical affordances are very useful. But I don't think the cause of DSLRs having them is because current manufacturers believe buttons have superior usability. It's because SLRs have had those same controls since before touchscreens existed and today's self-selected DSLR camera audience specifically wants products with that "vintage" user experience.
My evidence is that today's cameras generally only have hardware controls for features that existed since before the digital revolution. Purely new capabilities (like file management) have not included corresponding new hardware controls. Likewise, hardware controls that are no longer that useful, like mode selectors, are still present.
To me, this implies that camera manufacturers are not just trying to provide a "hardware control" UX, they are specifically providing "the hardware control UX of 90s SLRs".
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.