The highest level of ADAS system I use regularly has facial attentiveness tracking. If you spend too much time drinking coffee or even looking out the sides of the car it will alert you and eventually turn off. So you're not spending a ton of time drinking coffee or reading emails.
It's really nice having the car just want to stay in the center of the lane and keep the following distance all on its own. It's less fatiguing on your hands and arms having the car feel like it's in a groove following all the curves for you instead of resisting your input all the time for hours and hours. It's incredibly nice not having to switch between the brake and the gas over and over in stop and go traffic. Instead, the only thing I need to focus on are the drivers around me and be ready to brake.
I've driven between Houston, Dallas, and Austin dozens of times with ADAS systems and another dozen or so times with only basic cruise control. It's way nicer when the only time I have to touch the gas and brake are getting on and off the highways. I'm considerably more relaxed and less exhausted getting to my destination.
Let's assume all these options are either the same price or an immaterial difference to the price of your next car. If you had an option for a car with basic cruise control or no cruise control, which one would you take? If the option was basic cruise or adaptive cruise which kept pace with traffic and operated in stop and go conditions, which would you choose?
And then there's the skill atrophy. How do you learn to perform in stressful situations? By building up confidence and experience with constant repetition in more mundane ones, which this robs you of.
Which makes me think: if FSD requires constant hands on steering wheel and concentration what is the point? May as well drive yourself.