I mentioned all the BLIS errors I got when I had the car in for something else and the mechanic said not to bother, it was probably working normally, as in not very well.
I think the audible warnings my wife's Acura gets for lane changes are way more useful than visual alerts on the mirrors (although I suppose both is even better).
I suppose some of the driving assistance stuff like lane warnings has helpful use cases, but maybe I overestimate the general public's ability to drive sanely, cell phone use, etc.
My Mazda gives a visual warning on the side mirrors when it detects a car in the blind spot, and an audible warning if you put your turn signal on in that direction. Seems like the best of both worlds. (for drivers that use their turn signals)