But the cost of that convenience is in giving random devices full access to both your LAN and the Internet.
You could VLAN them into a separate audio-devices network and whitelist their Internet access but the effort in doing that would seem to outweigh any advantages of network audio devices.
Sometimes a dumb, network-unaware Bluetooth audio sink just works...
I've never found either Bluetooth, or the Sirius app to "just work". And Sonos is an established company, their speakers aren't "random devices" in the same sense as random IoT devices from Amazon.
You could VLAN them into a separate audio-devices network and whitelist their Internet access but the effort in doing that would seem to outweigh any advantages of network audio devices.
Sometimes a dumb, network-unaware Bluetooth audio sink just works...