It has all the path data
Source: I just tested it
Sorry, only London available
If you want to experience offline maps, you gotta go to London
Uh, but…OsmAnd is a phone app. So you’re saying you used the website on your phone’s browser, then? I’m not sure if that has an offline function, though I never used it myself. Does it say it has that function? Otherwise I think you will have to install an app, first.
Maybe you downloaded the offline map files, but had nothing to open them with. Apps use their own versions of the map files, by the way, those files you download from the website are for other use-cases.
OSM is great for everything non-commercial. Hiking path, finding a playground, public toilets or even the closest with few benches to eat a sandwich.
But for everything commercial and car navigation google maps is unfortunately much better.