Depends on the manufacturer. My Mazda's guidance system was fantastic, always worked, never crashed, and was fast. The interface- which unfortunately Mazda is moving away from - was a simple rotating knob and a few buttons arranged around it. Once you learned how it worked, you could run all of it without looking away from the road.
Meanwhile, on my current Honda I can only use Android Auto: which continually crashes, works super slow in some apps, and often just freezes for up to twenty seconds. I've got a secondary Sirius transmitter tied in because the car didn't ship with it ( only high end trim now get it), and the built in system randomly decides it won't let my Sirius Bluetooth connection play audio in favor of my phone. When I reset it to allow audio on the Sirius device, it simply goes back to what it wants to do when I restart the car, but only maybe every third or fourth time. I can't totally disconnect the phone because I need it for calls and Android navigation. So in this case you're correct, the Honda system is a terrible mess.
Yes, some of these issues could be my phone, but in the end having a built in system would alleviate this issue.