I have gpx tracks for every road in my city collected while riding my bike last summer. I used them in JOSM to update the local maps, but should I also upload them? I uploaded a few for new areas where the Bing imagery shows nothing, but am not sure if there is any value in uploading the rest.
Perhaps they would have more value if the recent acquisition of Bing Maps by Uber leads to that resource no longer being available in the future.
Definitely upload them for a at least couple of reasons.
First, it provides a record that a OSM mapper actually did a survey of the area in person. That is useful for quality assurance and possibly legal reasons (indicating the data wasn’t just copied from elsewhere).
Second, at least in my area there are places where roads are not really visible in the public domain satellite imagery due to tree cover. Having GPS tracks helps align the roads and trails. And one of the issues with GPS is there are errors, especially with the low end GPS hardware found in many smartphones. So having multiple GPS traces for a road or trail helps average out those errors and gives us a better shot at getting the geometry correct.