We're in a climate crisis and everybody should drive less when there are alternatives available.
Waze should help with that by suggesting Public Transportation or bicycle routes when selecting a destination, when those routes are viable alternatives (don't bother showing a 3h bus route for a 10 min drive).
This could be similar to Google Maps and use the same data.
Just by showing that there are alternatives, the user might be tempted to try them.
This might be specially useful when driving in cities that have car restrictions, dedicated bus lanes or good bicycle infrastructure that rivals congestion, where driving takes longer than the alternatives.