You must be using google maps :) I have a garmin standalone unit, and android on my dash, making it easy to contrast and compare. Google likes to pick the clinically shortest route, expecting that traffic lights and left turns take no additional time. When ignoring them and taking a more sensible route, you find that their elaborate complexity by their own calculations would have made at most 1 minute of difference.

Google has been improving over the years, but still hasn't caught up with the user friendliness of garmin. Garmin seems to give the kind of directions that a human navigator sitting next to you would. Google seems like a machine that knows nothing of the real world!