There's no google office where I live, but google maps will show detailed transit information including exactly where on its route the bus you are waiting for is.

There's an attribution saying the data is coming from the local metro provider, who has their own interface for accessing the same data, but having it in google maps is nice as it integrates well with other navigation.

So I would say it comes down more to who has partnered with google to make the data more accessible.

Maybe more anecdotal, but I have had great mileage with google maps for navigation while driving too. The government department for land information does make almost all GIS data publicly available which probably helps too.