In my experience the driving-behavior part of my brain can run virtually autonomously, like how you don't really have to spend 100% of your brain to walk down the street. This means that the words-thinking part of my brain is almost completely free, with the exception of short high-attention spikes for risky maneuvers like onramp merging. This is why listening to music or podcasts is a very popular driving activity. In many places even handsfree phone calls are allowed as long as both hands are available and your vision isn't obstructed.
I would contend that listening to a podcast or being on a handsfree phone call would be on par with the Claw Phone.
Daydreaming or zoning out while driving is reckless behavior. You should be fully occupied by the task at hand. If you aren't, find a parking lot to doze off in instead please, or call an Uber
> In my experience the driving-behavior part of my brain can run virtually autonomously
It can, but I've heard quite plausible claims in the past [1] that you shouldn't let it - because that's one of the things that kills motorcyclists. Your autopilot brain is looking out for other cars quite effectively - but a motorcycle isn't a car, and can slip through un-noticed if you're mind is engaged elsewhere.
[1] Citation needed, but lacking I'm afraid!
I find there's an asymmetry between listening and speaking. It's fine for someone else to tell me about their week, but I can't reciprocate with the same level of detail.
I suspect when driving demands attention, it's easier to buffer incoming words to handle a second later, or to simply miss portions and recover.
In contrast, a buffer of outgoing words between mind and mouth is harder to manage, and people prefer not to fall silent in awkward socially-unacceptable ways, especially if the other person might not see what diverted you.