8 years later, Apple Maps still doesn't show buildings in Russia, even in largest cities. So it's essentially useless for actual navigation. It's okay-ish when all you want is to see a point on a map in a city you know, and that's about it. Out of other companies, Yandex and Google have by far more detailed maps.
This leaves me with one question — why does Apple reinvent it anyway? Why can't they just use ridiculously detailed OpenStreetMap data (with appropriate attribution) and call it a day?
Because Apple learnt a long time ago that something essential needs to be in their hands; third parties let Apple down.
Google let Apple down by refusing to allow Apple to craft vector-based maps, only allowing Apple to download bitmaps. Thus Apple Maps.
Intel let Apple down by failing to predict where the market was moving since about 2012 or so, with the Core processors not gaining much in terms of performance and somehow managing to guzzle more energy. Thus Apple Silicon.
Plenty of other examples where Apple realised they can't offer the whole package until they own all the components. The formula is "<Company> didn't do <Thing> and it impacted Apple's offerings. Thus <Apple Thing>".
Good point, except OSM isn't dependent on any company or person in particular. It's a community effort. Apple could as well contribute whatever improvements it deems necessary to benefit themselves and everyone else. They could write their own renderers and whatnot, it's been done many times by different companies. It would've been a much better starting point, too, than whatever proprietary data they licensed to get started.
> than whatever proprietary data they licensed to get started
I detect a bit of a fallacy in what you're saying, that Apple wanting to have control over their own geographical data must mean that they aren't using or contributing to OSM. It isn't a zero-sum situation.
Probably why Google still has separate Waze and Maps maps. One is where users meticulously keep everything up to date, the other is where you copy those updates and can sell this as your own product/service.
This leaves me with one question — why does Apple reinvent it anyway? Why can't they just use ridiculously detailed OpenStreetMap data (with appropriate attribution) and call it a day?