Phone books were useful at one point, though less so for individuals.
Not saying you’re wrong but it reminded me of a moment when I was a kid. I was all of five years old when I got lost in rural Arizona. I was visiting my grandparents and my cousin and I went out looking for turtles after a monsoon the night before. I got separated from my older cousin and then lost. I wandered around for hours until I found the main road that led through a nearby small town. I managed to hitchhike to the local trading post where the clerk managed to find my grandparents phone number to let them know they had found me.
They were sometimes useful. Also, they were great for prank calls.
I did the same thing. I just want a product or service that doesn’t leverage AI. Mozilla’s resources are better spent improving the web.