Google does have a nearly impossible task making Maps work around the world, and I think it does an admirable job. One just has to have a bit of local knowledge to work around the quirks. For example, the walking directions Maps gives for Singapore are usually ridiculous. They're almost always twice the distance they need to be, since it's very common to cut through the open lower floor (void deck) of apartment buildings (HDB blocks) to get anywhere on foot here. I typically just use the walking directions to get a bearing, point the compass pointer toward the destination, and start walking in as nearly a straight line as I can, ignoring the circuitous path Maps suggests.

Driving directions on the expressways here are also spotty. If I wait for Maps to tell me to exit the expressway, I'm already at or past the exit. I basically have to already kind of know where I'm going to make use of driving directions (you know, like we used to do with paper maps). Never mind that there are actual bugs in the directions: at one spot on the Ayer Rajah Expressway (AYE), if I need to exit onto the MCE, it tells me to exit onto the AYE, which is incorrect).

Still, I guess it's better than nothing.

And another one I just thought of: If I ask for driving directions to a mall or office building (here in Singapore, anyway), it nearly always sends me to the taxi drop-off, not the entrance to the carpark. I have to drop a pin on the carpark entrance (which presumes that I know where it is) to get sane directions. Otherwise, I end up on the wrong side of the building in gridlocked traffic trying to find the carpark.

Google Maps can be downright dangerous in its lack of knowledge, and it'll make routing decisions that other GPS devices don't make (despite similarly working around the world). For example, it cannot comprehend the idea of country lanes in the UK, where e.g. TomTom can. Country lanes are narrow, twisty, and single file with passing places. But they're "national speed limit", or 60mph. You will never, ever go down one of these at 60mph. In most cases it's flat out impossible. Google Maps thinks you can go that fast.

If enough people using google maps have been down it in the right time frame it'll know the road is slow and account for it in time calculations, and generally not send you down it. The fact that no one using google maps has ever managed to go down that lane at 60mph never seems to enter into its consideration.

I've never had TomTom send me down a country lane unless it's literally the only way to get to where I'm going.