My alphabet scroll bar (like the one seen below) is gone for artists. I use this function all the time & now have to scroll through hundreds of artists... it's the worst. I haven't tried reinstalling because I don't want to lose all my downloaded tracks. Please help!
Spotify is always updating their app and trying out new features to improve user experience. They feature might have just been temporary, and might have been testing it out for a limited time to see how users like it. You can always request a feature here.
Also, in regards to reinstalling the app, the loss of downloaded songs is only temporary, you can always redownload all your music (as long as you have premium) after reinstalling the app!