But if you care about this why do you want wireless speakers in the first place?
You mean as opposed wired speakers? Why would I want to have to leave my phone plugged in?
You already admit to it having a battery.
I don't care about needing to leave the speakers plugged in though, I've never really been the type to carry a speaker anywhere.
It's already not green.
Fwiw I don't use Sonos speakers personally, but also I doubt any speaker manufacturer is particularly green. I use a few Google home minis, you can play to a group of them at the same time or just one. Really convenient with Spotify. I do have to use Sonos speakers at work though and their app is fucking garbage, if anyone from Sonos is reading this fix your shit. I should not be struggling to link 8 ethernet-attached speakers together ffs.