On mobile its navigation is terrible, takes you into strange routes that might be technically faster but are hard to drive at or sometimes non-existent. Sometimes tries to be smart, makes everything worse. i.e. suggest a route that it says its 5 min faster and shows no traffic and you find out that there's no traffic because of a road closure further ahead. The UI when driving is not as good as the competition. I only use it because it has superior business listings with decent reviews and photos.

On desktop the web app is jittery, occasional freezing of UI, buttons stop working(most often the street view figure just doesn't show the available street view or would refuse being dropped at a location). Textures wouldn't load, sometimes will downgrade the UI to non-webgl version.

Also, businesses are often frustrated when it comes to changing their address, no proper support exists to fix mistakes or do updates.

I would loved if EU forced Google to open its maps business data for a year for download so competing services can achieve parity in this regard. After all, Google has this data because its a monopoly - people simply uploaded their photos and reviews to Google Maps because most people use it because Google forced it down the throat of everybody.

Ah, also Google is pretty evil when it comes to maps. They jacked up the API prices to ridiculous levels once the become the absolute dominant service and they also tried to make iPhone undesirable by not making their Google Maps app in some countries when Apple screwed up with Apple maps and Apple maps was practically useless outside the US.