In trying to find privacy-oriented map software, I found OsmAnd as well as OrganicMaps and shortly thereafter began contributing to openstreetmap. It’s actually quite easy and IMO fun to find discrepancies and use your knowledge to help an open data set.
Not only have I seen my edits show up in proprietary softwares, but the area around me is more accurate, to the point where recent construction to the road network was updated on OSM and Apple Maps, but not Google maps.
I just checked and Google maps is still out of date.
Those EXT4-fs write access unavailable errors look spooky. Should probably do some standard Linux FS testing (fsck)
I’ve not had to recover anything from a raspberry pi SD card, but in the case you start from scratch - and considering it’s upset at write access - you may be able to plug it into another machine and at least salvage bits of its configuration that way.