[bathtub365]

They run a routing/cross-auth system so you can stream from other IP-based audio services directly to your speakers. They aren’t entirely a hardware company and those integrations are a value-add for a lot of consumers. I think you should be able to run them in some kind of offline mode, though.

[ClumsyPilot]

Or it could be smart enough to communicate with my computer directly, and have my credentials onboard, the way my NAS or router does.

Devices that used to be smart way before all this "dumb home" stuff appeared.

[greyhair]

Logitech Squeeze players also had Squeeze network, which cost nothing, and is still in service today.

You can put a DAC on a RPi, install squeezeplayer, and attach to the squeeze network for free today. I have done that exact thing in the last six months.

[jacquesm]

Even that does not require a server for the speakers to connect to owned by Sonos.

[bathtub365]

That’s true, but running and maintaining one is outside the expertise of most people.