This was one of the reasons why I left Spotify. There are hundreds of posts about this issue on the Spotify community site, e.g.
https://community.spotify.com/t5/Content-Questions/Option-to...
https://community.spotify.com/t5/Content-Questions/Spotify-P...
https://community.spotify.com/t5/Your-Library/I-Sent-a-Playl...