I agree that that's the ideal way to do this, but it's just not always an option.

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.

Yeah, it's tough because to be the Single Point of Truth, you'd need to be the List of Parking Places in the Netherlands, not just the accessible ones that you care about. You might even need to be The List for Europe.

Being The List of anything is a big, thankless job filled with nonstop toil to keep it up to date. It's not something you want to do unless it's truly your passion or somebody is paying you (a lot) to do it.

The problem is that building to tools to Be The List is pretty straightforward and fun. You only learn about the toil you've signed yourself up after the fact, once people start relying on it.

Good luck!