It's been for years that the Spotify mobile app has unresolved slow- or no response issues. For instance,
- it might take 1, 5, or 10-30 minutes from starting the app to playing music,
- it seems often it is hung on network, or checking playlists, or computing hashes, I don't know since you don't tell, it's just waiting,
- it loads playlists forever, then it doesn't.
You should make sure the obvious:
1. The UI should load fast and remain responsive, no matter how blocked the app is on network or storage. When it must wait, tell the users what's going on.
2. Make sure that downloaded playlists can start playing right away, while you are doing checks or updates in the background.
3. For online playlists, prioritize playing music over doing background sync/checks/updates.
4. Adaptive/proactive caching and buffering. Take into account that users tend to keep huge playlists on storage cards rather than device storage. Make an option to select at least one playlist that is optimized to load fast (at least the first couple of songs) even from storage cards. (Similarly with loading from network vs slow network, though this part and network buffering should probably be fine, most delays appear during the loading phase. It appears to me you only have problems when initializing the app, and the bottleneck there seems to be some political policy rather than lack of technical knowledge, since I'd like to believe every single one of your software engineers can solve these problems. So please allow your engineers to fix them).
Until these are fixed, the mobile apps are mostly useless and frequent cause of meltdowns of various magnitude.
I am often resorting to use the browser app to control devices via Connect, that's way faster than starting a mobile app and waiting for the playlists. This is a shame of an app implementation in 2021, still not fixed, since 10+ years.