I still have my good old Squeezebox Touch controlled by the iPeng app (on iPad)
(I’ve had the Touch long before the concept of the Essence/Core was born)
It is nowadays connected to the line-in of my Essence box....and (the sound of it) can therefore be distributed over my NL.
I don’t use it very often anymore, but won’t let it go (access to my NAS collection, Spotify and netradio).
If you don’t need the NL-functionallity of the Core, don’t want the B&O X app as a controller and you aim at a standalone setup, there are lots of other possibilities on the market.....from resonably to insanely high priced!
With the Core you get AirPlay, ChromecastAudio and bluetooth - something, that the Sonos can’t bring on its own.
The concept of the Core is versatility - it can be used in different situations/user cases, with different preferences (and in a NL-setup, if you want to).
Not everyone need all these functionalities - if you have a specific preference, there are lots of alternatives out there. Some people are happy with a ChromeCast Audio dongle (with the right settings).
MM