I don't really use it often as a user nor i my projects to have a definite opinion. There is some pairs of words (about 5K) in Sino-Vietnamese that came with their chu nom writing which was very helpful to one of project. Otherwise I think it lacks structure and can't be harvested automatically easily (I don't think Wikidata integrate it all, and that website is a non-starter for me). Also every language is structured differently so Wiktionary can hardly be commented as a whole.