I run valideparkeren.nl, a crowd sourced overview of all accessible parking spots in the Netherlands. Ideally, there should be a government-owned single source of truth, but the whole reason for starting this is because that source doesn't exist yet. I'm starting to work with the government to eventually hand this project over to them, which was the goal from the start, but the only way to make that happen is by first becoming the source of truth.
Edit: I was also planning to add my data to OSM at some point, but I'm reconsidering that after reading this. I completely understand that they only want high quality data, but in my case I'm convinced that high coverage and slightly lower quality is better than low coverage and high quality. Of course, transparency of how sure we are about the data is vital, so users can decide the risk they want to take.