I’m a bit confused why you wouldn’t directly contribute to OpenStreetMap. That database is already in-use by many- further splintering of open alternatives to proprietary mapping only hurts the FOSS community IMO because we need as many hands on deck as possible with OpenStreetMap making the data better and feature-rich to maintain any semblance of parity with something like Google Maps.
I believe Mycroft is no longer supported due to legal battles
https://mycroft.ai/blog/update-from-the-ceo-part-1/