On YouTube, by far the best is Easy German. Their playlists also divide the content by levels from A1 to C2, as well as by theme:
https://www.youtube.com/@EasyGerman/playlistsThey also have podcasts: https://podcasts.apple.com/de/podcast/easy-german-learn-germ...
More generally, there's also good podcast content from:
• DW news: https://podcasts.apple.com/de/podcast/langsam-gesprochene-na...
• Coffee Break German: https://podcasts.apple.com/de/podcast/coffee-break-german/id...
> I can read children's books but every native speaker sounds like they are zipping along at 2x speed.
I generally play most of the podcasts at double-speed precisely because of this. Real speakers are much faster than the careful slow pace of most internet content, and double-speed playback forces me to develop gist-comprehension even if I miss the odd word here or there.