I am constructing my own. Examples are drawn from books, group chats, podcasts, and other media that I consume in the target language (so I know those are either correct, or at worst, as wrong as native speakers are which is good enough for me), shortened as necessary to make it appropriate for Anki

Then I gave my first 100 cards to a native speaker and somehow it's still full of subtle issues and not infrequently also actual mistakes >.<

The two dozen decks I've downloaded aren't always perfect either, but making your own doesn't guarantee it'll be better than another uploader's honest attempt at making a good deck. I do wish Ankiweb was more collaborative though, at least having a bugtracker where people can report mistakes and additions, if not full on code forge functionality. If I'm not mistaken, all you can currently do is leave a review