This seems like over-optimizing for time. For the individual there are trade offs in wear and tear, fuel consumption, stress, accident risk, and as a sibling comment indicates, a social component.

For traffic in general this increases the number of lane changes and merges, increasing risk and slowing traffic further. Depending on location it may benefit by using more of the road surface (and alleviate problems further back) or may cause problems off the freeway at the local exit either due to greater traffic at the intersection or the freeway queue backing up into surface streets. (Or both.)

It should also be noted that this is an illegal maneuver in some US states. I presume Waze doesn’t suggest it in those states.