Can't play downloaded songs.

[Andrewnogo]

I have songs from bandcamp.  They are on my phone.  Apparently, Spotify doesn't care about its customers because in 2020 we still don't have the basic functionality of playing music stored on the same device the app is installed on.  So I jumped through all the stupid hoops of putting the songs on my PC (even though they are already on my phone.) and putting them in a playlist and they play on my PC fine on the desktop app.  I went to the playlist with them in it on my phone and clicked download and it says "downloaded" and yet I can't play any of them on my phone.  I have fought this stupid BS for like half an hour now for BASIC functionality of a music streaming app and jumped through all the required hoops (It's in a playlist, both devices are on the same wi-fi, both download buttons are pressed, I don't know what else I'm supposed to do because those are the instructions given to me to do this incredibly basic thing.) and I still can't play my music.  For what?  Why can you not just do right?