Huh. That is the reason I used waze: it's the only app that would take advantage of back streets.
I would agree that Maps and Waze strike me almost as opposing forces in how they do things … without making it apparent.
This is exactly why I hate Waze: people "scooting around" are exactly the worst ones to have on residential back-roads, where children might be playing, people sleeping, and where there's less often a cycle path.
Fortunately, traffic engineers in the larger European cities sometimes block off residential roads to cars to prevent "rat running".
Maybe routing apps should have an initial onboarding (or route-specific questions) similar to 401(k) / investing apps: "what is your tolerance for risk?" and "how well do you know this area?" and "do you like calm or active routes?"