The problem is that Spotify is losing money each year. They aren't profitable. And if they are keep focusing on music, they never will. Their deal with the music labels says that they need to give 70 % of each subscription to the music labels. So by getting more people to signup, they only marginally increase their revenue. Same goes for raising their prices.
Thats why they tried focusing on Podcasts and Audiobooks. Those are a lot more profitable, either by adding ads (Podcasts) or by charging a premium (audiobooks).