Take a look at your playlists, there's a good chance some are in need of a little TLC. Here's some tools I use to make sure my playlists are always in good order.
Remove duplicate songs
Spotify Dedup is a nifty website that removes duplicated songs from your playlists and saved songs.
It can be found at https://jmperezperez.com/spotify-dedup/
Remove unavailable tracks
These could be songs that have since been removed from Spotify, or are only available in certain countries, to some users they will appear greyed out and are unplayable. Here's how to find and remove them.
On the desktop App, go into settings and select 'Show unavailable songs in playlists'.
Either way, if someone else has this option turned in wouldn't it be nice that they don't see songs that have been on your playlist for multiple years.
Find some new music, or discover a new genre
Glenn McDonald has the very cool title of Data Alchemist at Spotify, and Senior Engineer at The Echo Nest.
http://everynoise.com is a deep dive into music genres, songs by city and so much more. I use this to discover new genres (Emo Trap or Pirate Metal anyone?). Here's the explanation quoted from the website "Every Noise at Once is an ongoing attempt at an algorithmically-generated, readability-adjusted scatter-plot of the musical genre-space, based on data tracked and analyzed for 2,908 genres by Spotify as of 2019-04-09". Yep, you read correctly... 2,908 genres at time of posting!