Re: Many happy non-returns
^^ this. 100% this.
This is home audio equipment, NOT consumer electronics. They're supposed to work pretty much until you get bored of it, it breaks irreparably or you fancy an upgrade. Then it goes to the flea market or boot sale (or ebay I guess).
The absolute oldest Sonos must be.... what.... 2005? That's absolutely not lasted long enough for a piece of home audio kit.