I use Spotify when I'm at home (connected to wifi) and also when I'm away from home (connected to limited data connection - 100MB per day), and every time I must remember to change the streaming quality from settings (Android app).
It could be useful to have a setting for choosing wifi streaming quality and another setting for data connection streaming quality
Updated on 2020-11-26
Thanks for coming to the Community, and adding your votes to this idea.
We're pleased to confirm we're setting this to implemented.
It's now possible to split Streaming into Cellular Streaming and WiFi Streaming via the Settings Page > Audio Quality, on iOS and Android!