I think if Waze did audio, they'd cause more accidents - usually I have Audible or Music running at the same time if I'm using Waze.

Perhaps that's why they're partnering with Spotify (well other than you can't run Waze on Carplay)?

I may be dating myself, but why would a waze audio ad cause accidents more than a radio ad? There might be logic to make sure the ad doesn't overlap audio navigation guidance, but that seems like a feasible constraint.