As a regular data contributor for Openstreetmap: Openstreetmap is terribly broken in many many ways.

There's no regular checkup of the data if it's still valid. Reverting is extremely hard and there are no checks for changing the data. The multipolygon model for areas can be extremely complex and is the cause that many regions aren't touched at all anymore. In many regions it's just an import desert where already open data gets relicensed under the more restrictive OdBL license. Those areas also only rarely get touched by mappers.