I noticed that a lot of books we bought are quite old and contain topics that we don't think are really suitable for children (lots of negative topics, or fear mongering or topics about punishment/bad things happen to bad people). Basically quite unconscious books.
Whilst we want to buy cards from yoto we've found many of the more conscious and positive value books aren't available.
We'd recommend finding books that are most positive and don't aim to make children anxious, and have a way to filter by themes or perhaps even year of publication date.
Examples like Oliver and Patch, and Waldorf books are a good start (check out the forest fables podcast https://open.spotify.com/show/05MIszNXK7GZeUuoWpLln9)