I also use the Spotify radios a lot, but they are heavily curated - they contain a lot of songs that you already have in a playlist or have liked. So they are useful for listening, but slightly less for strictly music discovery.
I use radios in a hybrid approach. I'll make a radio, find a song I like, and then go play the album through and let Spotify start recommending, and repeat. Tends to make enough variety to get me to all sorts of interesting places
Something useful I found is the "Go to song radio" in Spotify, that creates kind of a "dynamic" playlist with similar songs.