Will Berlin's monument to German Unity ever be completed?

A memorial is being built to celebrate Germany's reunification. It was supposed to be inaugurated four years ago. Now no one knows when it will be ready. What makes it so controversial?

source https://www.dw.com/en/will-berlin-s-monument-to-german-unity-ever-be-completed/a-66940631?maca=en-rss-en-ger-1023-rdf