My experience is anecdotal and is with two rental vehicles, so take it with a grain of salt, but…
I’ve had two Toyota rental cars recently. Both the adaptive cruise control and lane keep assist sucked. I took two long road trips from Denver to Kansas City and back, so quite a long and relatively straight stretch of road. I own a 15-year-old car that doesn’t have this technology, so I decided to give it a go (I really had no choice with the adaptive cruise since it’s on by default).
What I found was the adaptive cruise control was wildly variable. I set the follow distance I wanted, but it really didn’t matter. Sometimes it would get uncomfortably close to vehicles in front of me, and other times it would start braking way, way too far back; it didn’t matter if it was a car, pickup, semi-truck, flat, hilly, curvy, whatever, but it was just so incredibly inconsistent. Lane keep assist wasn’t much better, especially while crossing windy Kansas. Sometimes it would try to take the exit, sometimes it would just leisurely weave back and forth in the lane. The worst was when I would get a large wind gust (which was quite common) and it would scream and swerve as it attempted to fight the wind and stay in the lane. I mainly keep lane keep assist off, but would occasionally try it out just to see if it was me imagining things or if it really was that bad. It was that bad. I also found that I had to keep my hands on the wheel firm enough to keep the features activated, but that often just wound up overriding the lane keep assist. I found it incredibly pointless and just a huge nuisance and waste.
The annoying thing was, since I was unfamiliar with the car, I couldn’t figure out how to disable the adaptive cruise control either. So while I could turn lane keep assist off, I couldn’t figure it out with the adaptive cruise control, so I just dealt with that headache.