Say you want to like a track and then add it to a playlist. It used to be a heart icon and a plus icon. Now they combined everything into a plus, but depending on your current context it either adds it to an existing playlist or to your liked music. Also, if a track is already liked I would expect to "unlike" it when clicking the now green plus icon. But no they had to make it show a context menu because they combined liking and adding to playlists. It's just so confusing, and the previous UX worked fine and was clear for everyone.