1. You're comparing an old, small GPS with a new, large GPS. My phone is larger than those old tiny GPSs too, but my GPS is WAY bigger than my Galaxy S7.
2. I don't, my GPS is normally plugged into my lighter.
3. My GPS tells me and shows me, I have much better visual skills than I do listening comprehension skills, I can just glance up and tell without having to pay much attention to it.
5. Sometimes you miss the signs if you're looking for other things.
6. I hate sound coming out of my phone period. Don't care if it's phone or whatever. I don't want to open up some stupid website with embedded video that auto starts and have it blaring. It's annoying.
7. I rarely talk on the phone, mostly I interact via text or email and voice to text is a big piece of crap. It was better on my Windows phone, but then most things were.
8. Definitely agree on the traffic updates, it's why I still use google maps at times, but usually in conjunction with my GPS.
Mostly though, it's what I'm used to (as I'm sure is the case for you). I keep my GPS at the top of my windshield right next to my rearview mirror. It's second nature to me that I can glance up and know how fast I'm going, what the speed limit is, how far it is until my next turn, and where I need to be. I usually look at it at the same time I check my mirrors, which is often when driving.
BTW, most new GPSs have a more accurate speed reading than most vehicles' speedometer. Mine varies significantly. My Mini is a good 5 miles off at 70, the Juke is 2-3 off, my S2000 hits it pretty close. I like to keep my cruise control at exactly 5 over so my GPS takes the guesswork out of that.
There are reasons that a body stays in motion
At the moment only demons come to mind