I think that as more automated control is introduced, driver attention significantly drops off, and people also tend to rely on the automation rather than controlling the car themselves. This leads to a drop in the standards of driving and driver ability.
If the car limits itself to the speed limit, there'll be a tendency for drivers to simply leave their foot on the floor leaving the car to limit how fast they are going. Either that ot set a higher cruise control speed and let the car get on with it.
In turn this leads to the driver having to pay less attention to what they are doing, so they'll not be thinking about what is going on, and not anticipating potential issues before they happen.
To give an actual example of something that happened to me fairly recently, I was driving on the North Circular in fairly heavy stop start traffic, so average speed below 10 mph, when I was hit from behind by someone driving a large Kia SUV. It wasn't a big impact, but enough to throw mine and my passengers' heads back.
We both pulled onto a side road and checked for damage. There wasn't anything visible, and as I was driving the "shed" car, I wouldn't have cared if there was a slight scratch or whatever. The interesting thing was the other driver's insistence that they couldn't possibly have run into me, because their vehicle was equipped with a collision avoidance system, so it was simply not possible for them to have run into me.
I suspect that they routinely drive in traffic not bothering to brake, but rather lazily relying on the collision avoidance to prevent them hitting cars in front in traffic, and for some reason on this occasion, it didn't work properly. An example of where automation allows the driver to pay very little attention to what is going on.
In terms of driving in general, much of the fun has gone out of it, unless one gets up at 6:00am on a Sunday morning to go for a drive out in the country. I'm certainly not interested in having lots of systems automating and controlling my driving, so, as someone above said, I'll be keeping my existing (currently 14 year old) "fun" car as long as possible with manual 6 speed gearbox, no stability control, no cruise control, no parking sensors, and no ABS. It even has manual winding windows (which I prefer to electric ones)!