Can you even imagine how relaxing it would be to have the same interface to your systems, every day, with all the parts in one physical location and never moving? Learn it once, then nothing changes for years and years, or if it does it's usually adding on, not replacing or re-arranging existing stuff? Man, that would be nice.
Especially if the interface was designed for high performance (unlike most UX today). One of my favorite was when I spent years starting to learn photojournalism on the side: the mechanics of using a camera is only a small part of it (it's mostly about understanding and conveying a story), but even at my student/amateur level, the muscle memory with pro DSLR and lenses was crazy-effective. I even got a shot that happ…
I'm in a phase of life where I'm not sure what I'm supposed to be doing or even what I'm very good at. But I do have a camera and I can write passable amounts of code, so I've been preparing a website to host my work while I strongarm friends and family into taking pictures with me. Most of them have a nice phone with a good camera and so we often end up talking about what the benefits are of a dedicated set of camera hardware versus using a phone's camera. I like those discussions because it makes me think critically about my camera and why I'm using it.
The physical inputs and muscle-memory laden experience is what I've kept relying on as justification and it's nice to hear I'm not the only one. For those of us who have used guns, it almost feels like holding a rifle. The entire process is subconscious and the more I use it the faster I become, as well as the more finely-tuned I can set up the camera during that subconscious movement. It equips me to image things that, if constrained by time or scene stability, I straight up would not be able to do with a phone camera.
There's also the social benefit that comes with it. I've found that when I'm using my camera and rapidly fiddling with controls and settings, people around me get the sense that I am a professional (I'm not) who knows what he is doing (I don't). "Everyone" has a phone so those "every" are common to see holding up a flat slab to a scene but dedicated camera users are increasingly rare. My tools and my physical control over them grants me this silly air of authority. And honestly that authority presents me with fresh opportunities for impromptu shots; just recently I was at a live music event and started wandering into places and standing on things to get the angles I wanted. Nobody said a word to me, nor did I think twice about doing it. We all kind of understood, "that guy has a camera and he's using it well. I suppose we should let him work". Kind of interesting.