Spotify playing songs not on my playlist

[Reenbola]

Hi, I am a Spotify free user that’s been using this app for a long time, and I have one problem. Why on earth did you make it so there’s shuffle play on IOS ONLY? On pc/tablet I can play anything, so why does iPhone suck, it makes no sense at all, and  is premium really necessary for listening to your own playlist without having it jam it full of songs you didn’t add or don’t like?