>>_bxg1+(OP)
Car dashboard lights meet most of these criteria and yet they are routinely bad. My partner had trouble figuring out the "flat tire" icon and they are a fairly intelligent, well-educated person. The icon was basically a circle with an exclamation point inside. The fact that it had a slightly flat edge actually made it harder to recognize as a wheel since we normally associate wheels as being perfectly round. It almost looked more like a steering wheel. There was no status code to look up, only an icon which they had to match visually against every other possible icon. And this is one of the most common warning lights to appear in a car, so imagine how much harder the more obscure ones are.
Roombas, which the article mentions don't use voice, actually did start using voice in the last couple of generations. And it's great. It tells you that it's stuck rather than just beeping sadly at you.
I'm not necessarily saying the car dashboard should speak warnings, as it may startle people on the highway, but I also think there's a lot to improve on.