I love my Garmin and use it regularly. Even when just heading to Denver where I know the route by heart, I still use it for traffic updates and arrival time estimates - usually quite accurate for highway driving, but not as much in the city because it only knows speed limits on streets. It doesn't have any idea about stop signs and traffic lights and doesn't factor them into driving time, which is why you will sometimes scratch your head when it tries to send you down a street that you know has many such impediments. It has mostly served me well many times in strange cities or in unfamiliar locales, even quite rural.
That said, I also have 2 2017 road atlases, Rand McNally and National Geographic. I also use Google Maps (both map view and satellite view) to get the general layout of a destination area in my head before heading out. I use all of those reference sources in conjunction with my GPS to hopefully ensure that I end up where I intended.
I am a huge fan of GPS technology, but I'm also well aware of its potential shortcomings, and I use it accordingly.