I want to remove, with a bot edit, project=opensidewalks and project=OpenSidewalks from OSM objects within USA.This debris is fortunately not used nowadays but it encourages other mapping projects to start using graffiti tags to mark what they “own”. In addition, this tags are absolutely not needed anyway to identify sidewalks - you can use footway=sidewalkfootway=crossing and so on.
It will take centuries to get rid of it this way and stay present all the time, current implementations remove discardable key not discardable tags, it is more effort to handle it this way (both for me and for developers of various editors) and does not have strong benefits (unless you consider “objects will be edited” to be a grave catastrophe).
The tag could be used to get an estimate of how much organised mapping is happening there?
Nah! taginfo shows only 21 thousand ways with these project tags. While there are 1 872 460 of footway=sidewalk in the US… That would make the project look not much of a success.
These tags aren’t representative of OpenSidewalks. In San José, the local community collaborated with the OpenSidewalks folks on a sidewalk import, but we never would’ve considered adding that kind of metadata to the sidewalk ways. We used hashtags in changeset comments for tracking purposes, but honestly an Overpass query of footway=sidewalk in the city is pretty much all we need anyways.