I created https://matkoniecz.github.io/OSM-wikipedia-tag-validator-reports/ that lists some problematic
subject:wikidata / etc tags.
wikipedia tags linking nonexisting articles or entries about humans (that typically are invalid, sometimes retaggable to
subject:wikipedia) and so on.
If you are interested in specific area - let me know by sending a message or posting here and I will add it (right now report for Belarus is being generated)
If any report is bogus, false positive, invalid or otherwise problematic: also please let me know!