I really wish Google Maps et al did a better job for subway/metro/transit stations with multiple entrance and exits. Oftentimes a station is shown as a single point on the map, while in reality the point(s) of entry can be a block or more away from what's shown. Likewise, choosing the right exit when you leave the station can save you multiple blocks of walking, depending on your final destination.
Even just showing the general shape of the station in 2D on the map would be helpful, though obviously this can be tricky when there's other points of interest above/below the train line.
Yep here in Barcelona it's like that too. Single point on the map even when there's multiple exits (there usually are) and not showing which entrance is closer to which line. Real pita.
Open Street map is so much better for this but that totally lacks live public transport info with delays etc. So I end up switching between both which doesn't help.
I've generally found they're all correct. Sometimes, I run into situations where a particular exit is closed because it's after-hours (some stations close certain exits when it's late), and Google Maps doesn't realize this, but I haven't noticed any exits being outright wrong.
I think this is probably a local issue: Google Maps is better in some places than others. Google has a huge office in Tokyo, in Shibuya overlooking Shibuya Crossing, so Tokyo is probably one of the best-supported cities in GMaps for this reason. Other cities might not have such accurate information.
Stations undergoing maintenance or upgrading may have certain exits closed or even temporary platforms that change as the project goes on. Here in Chicago, the Red Line is undergoing a major rebuild that started over 2 years ago and will not be completed until 2025. Temporary stations have been set up at multiple stops, with different entrances that have changed as the project has gone on [1].
It may have only changed a few times over the last 2 years, but it's certainly a rude awakening when you're running to catch the train and you find out your stop is now a block away from where you thought it was.
Even just showing the general shape of the station in 2D on the map would be helpful, though obviously this can be tricky when there's other points of interest above/below the train line.