Have you looked at Spotify’s settings recently? Volume Normalization (Set the same level for all track) has moved from “Advanced Settings” to the first settings page, and you can choose Loud, Normal, or Quiet. With Loud, they restore their previous settings and land at about -11LUFS, with normal -14LUFS and Quiet runs as low as -22LUFS! If you let me decide, put it on quiet and adjust your playback gain with your amplifier to a level you’re comfortable with, this way all music from Metallica to Mozart will work together without any problems with limited peaks or volume.

My colleague Sigurdor Gudmundsson’s have more details in this blog post: http://siggidori.wixsite.com/skonrokk-studios/single-post/2018/06/04/Spotify-is-now-more-dynamic-than-ever