AFAIK, this is not really accurate; Google Maps, Apple Maps, and Waze often pick different routes between the same two points at the same time of day in my (admittedly informal) experiments. Google and Apple pretty consistently favored major roads unless there were serious traffic backups on them, while during anything remotely resembling commuting hour, Waze was frequently acting like your crazy uncle who swears taking 28 residential roads, two of which are unpaved and the last of which is an alleyway that ends in an unprotected left turn across three lanes of dense traffic, is clearly the best route.

(And while that's an exaggeration, Waze has consistently been far more likely to send me down unpaved roads, ridiculously steep hills, and, yes, unprotected left turns onto busy highways, presumably because the residential road I was on was lower traffic than the parallel road one block away with traffic lights.)

That was similar to my experience but I haven't used it in several years, shortly after the Google acquisition my account broke. Waze seemed to want to route me through school zones all the time. Google Navigate didn't seem to suffer from this quirk. It never occurred to me that those quirky routes could be due to competition in an anon social network ranking contest.

Waze feels more like a social network. You get a little cartoon car avatar to represent you and can see other people's avatars on the map. There is a leveling/experience system for your character. Waze also allows the user to manually share the location of speed traps and red light cameras.