You’re not the target audience. Why do you have Sonos gear? Your use case doesn’t seem to make use of any of the primary features.
Most people use the Sonos app because a) it is how you control playback across multiple speakers throughout the house, grouping/ungrouping, volume levels, adding to queues, etc, b) without the app you can’t have playback that doesn’t come out of a device: you have to keep one person’s phone physically in the house and burning through battery in order to stream from it, and you can’t keep audio playing when they leave, or have music start up at set times independently of who’s there, and c) you can’t create a playlist that uses multiple services, or local storage, at all.
Sonos without the app is just an AirPlay speaker, and that’s not the same thing at all. Sure, Spotify Connect is fairly robust, but it didn’t offer high quality audio until like a month ago.
Again, it sounds like you would have been better suited with standard airplay speakers, I’m not really sure why you have Sonos at all.