For example, lots of popular artists in Japan (not trying to cherry pick something obscure; Japan after all has the second largest music industry in the world) don't even have an article there, let alone a complete discography.
This is obviously due to lack of volunteers, or their volunteers have limited areas of interest, which is totally understandable. But I think some basic automatic systems to at least add the new releases from major labels is needed for such database.
I personally have a better experience on https://musicbrainz.org/. It suffers the similar problem mentioned above, but much better. At least most of "mainstream" artists I checked, it has complete or close to complete discography. It is also a more "ambitious" database, which has data for each track, recording (my fav part), etc.