Spotify does not support the purchasing of albums as they are solely a streaming service that pays the artist per listen instead of purchase of the song or album. If you would like to purchase an album or song, I would recommend via the Google Play store if you use android if you would like it on mobile or PC. If you want an actual CD or Vinyl copy, I would check out Amazon.
Why would they roll out the ability to purchase and download music, then take it away in the last five years?
Have they ever heard of DJs? Or people who like their product, but don't have the data to stream in the car? "Focusing on improving the streaming" is not an excuse to take away a feature that they already rolled out.