I've definitely had some bad experiences with GPS.

Telling me which way I need to go far too late. Too late to get into the right lane to take the manoeuvre it recommends.

Misunderstanding the lanes so it seems to be telling me to take the next left, when what it actually means is continue straight at not just the next fork, but the fork after that, and then take the next left. (Seriously. This exact scenario happens so reliably to me on one major route near me that I've learnt to expect it.)

Routing me through a rat run of minor residential streets when the major roads aren't even close to congested. Often involving an unprotected, unsignalled right turn across traffic to get back onto main roads, where I have to just hope there's a gap in traffic in both directions at once. There are a few places it likes to do this that I've learnt to avoid, but that's in cases where I'm not really relying on GPS for navigation per se, but to find which of the multiple routes I should take today (and because having GPS on is the only way to get it to show me GPS speed and enable the convenient podcast controls).