I've had Google Maps (desktop web browser) give me a route once through heavy traffic, but when I dragged the route to a mostly-parallel highway, my estimated time decreased by 10 minutes. So it's not perfect, or they wanted more users to give more data on the traffic.
With Waze, it almost always tells me to get off the highway at a certain point and then take a parallel (smaller) road to work. If I, as I now almost always do, ignore it and drive past the exit to take one couple miles down (and much closer to work) I can see Waze's ETA dropping by a few minutes. I complained to Waze about it, bit don't see any changes so far.
OT: I'm livid at all the efforts to punish drivers for driving (like the toll etc). We aren't driving for fun! I bet most of us would prefer not driving. I try to work from home when possible because driving in commute hours is a terrible waste of time.
I don't have big problem with tolls, as long s they are not on taxpayer-funded roads, and actually get you something. Not just the privilege of crossing the bay instead of driving around the Bay.
Disclaimer: I usually do use Waze commuting, but find its suggestions in certain places downright bizarre.