I love the Radioplayer and to date I can’t get my head round Sounds. It just hasn’t got the same functionality unless one wants to listen to music. Radio plays, comedies et al are my listening menu. It seems that things are gradually being removed from the iPlayer. I’m old so not important to the new BBC.
But one thing iPlayer Radio has never been very good at is content discovery. You really have to know what you’re looking for, where as Netflix or Spotify are pretty good at the “you like these genres, so you’ll love this one!” game.
I believe this personalisation aspect is what BBC are trying to solve with Sounds.