I generally agree, but heading north on I-5 from LA to SF is bumper to bumper traffic constantly swinging between 50 MPH and 75 MPH. Normal cruise control is worthless here because you're never going the same speed long enough to be a net benefit. I would absolutely love adaptive cruise control plus semi-automatic steering in that one scenario.
Stick me out in the middle of nowhere and I'm perfectly content driving for hundreds of miles straight. I don't find myself in that too often now, though.
This is purely anecdotal, but I've found driving like a "grandma" makes the drive completely stress free even in bumper to bumper traffic on the freeway. Just pick the center lane and set the cruise control to just around the average speed of that lane. Sure, I might arrive 5 mins latter and annoy some impatient people, but it does the trick most days. Hopefully more people start doing this and we can reduce phantom traffic jams.
That's absolutely the sane approach: shoot for the middle of the pack. It still never fails that someone races past me and cuts in, then forgets that their car also has cruise control and sucks at manually maintaining a constant speed.
Stick me out in the middle of nowhere and I'm perfectly content driving for hundreds of miles straight. I don't find myself in that too often now, though.