Seemed verbose, overengineered, unnecessary framework introducing complexity. I didn't see a strong use case for it, maybe for a lack of an obvious one or my understanding of it.

It also didn't leave a strong impression. I had to look at the site and goal/description to remember.

Maybe some niche data handlers and implementors have use for it. But a Wikimedia project seems overblown for that.

I have not used it though. I'm open to being shown and corrected.