What Is Sonos? How the Speakers Work (and What They Work With)

You left out the Sonos Connect that lets you use Sonos with any powered speakers, and audio or home theater system. It has digital audio output so you can use a DAC of higher quality than the built in one.
You also left out the Sonos ConnectAmp that allows you to use Sonos with any 1 or 2 pairs of passive speakers.
The Sonos speakers are fine but either of the above will allow for potentially superior sound quality.