The response is to “it didn't occur to me that people might not remember how to get places in real life”, which is a rather limited understanding of why people might use navigation. I am not here to preach to you the benefits of this technology, simply clarifying an additional use case. There’s no need to conflate your own needs or tastes with the rest of the driving populace, either.
Also, those notifications can likely be conveyed using audio-only warnings, anyway. Making all of this discussion a bit moot.
Finally the entire benefit of live navigation is to find alternate routes with less traffic! That is something you could literally do about.
Most of the places I drive, there aren't really any practical alternative routes that don't add several hours and often things like a ferry journey to your trip.
I don't want audio alerts for anything either. It's really simple - I don't want anything in the car that beeps, flashes, lights up, makes noise, or indeed does anything that is not directly part of making the car go in the required direction at the required speed.
Okay, that’s fine for yourself, but as seen in this subthread, other people have different tastes, and needs.