Using the web API, I can only see 1438 official Spotify playlists (all the way up to "foodora dinner playlist").
I'm getting the playlists recursively using
for i increasing in increments of 50 until the API request returns nothing.
There are items which don't appear in the list, but which are Spotify-owned playlists. For example the playlist with ID 37i9dQZF1DX0QKpU3cGsyb does not appear in the returned JSON from the iterative process above, but is authored by Spotify and its details can be accessed via the API directly.
Why are not all of the playlists showing up?