Anecdotal, but still: I used to drive an Audi with a ton of advanced L2 systems (adaptive cruise control + lane assist). Both systems work from standstill to ~180km/h (well above highway speeds). While not perfect, I did use them both all the time, and the way you drive changes. You learn 'how' the systems work really fast.
The thing that changed for me while driving with both systems engaged is that my role changed from driving and continuously making small adjustments to stay centered in the lane and keeping the right distance. With the systems engaged, I was mostly monitoring that they work accurately. I don't have to bother continuously with most things, I can spend more time watching all surroundings to watch for anomalies / things the systems can't handle.
The end result for me at least felt a lot safer, and more relaxed. The systems felt very, very reliable.