As an OpenStreetMap contributor I'm extremely grateful they are correctly attributing OSM (by the sounds of it).

There are plenty [1] of sites & apps (some quite large) that don't correctly attribute OSM data according to the legal requirements [2].

[1]: https://wiki.openstreetmap.org/wiki/Lacking_proper_attributi... [2]: https://www.openstreetmap.org/copyright

That makes sense.

I have heard some folks throw shade on MapBox, but it appears to be a pretty good system, from what I have seen.