Consumer Rights Act UK

Not necessarily - you accepted the terms of the EULA when you implemented your system and its updates.  This expressly states that the software can be subject to whatever changes might be made and that any existing features are not guaranteed to be continued in subsequent updates.

Sonos is a multi-billion outfit with appropriate legal support - unless you are within a statutory guarantee period, or can demonstrate demonstrable physical or mental injury through use of the equipment, then your choices of recompense are very limited.

It's consumer capitalism!   

Take a break and relax with this :

Even though the CRA 2015 supercedes any warranty offered by them? I'm within six years of purchase and saying that "existing features are not guaranteed to be continued in subsequent updates" surely can't cover rendering the entire system unusable? It's like buying a Tesla only for them to brick it with a software update and being told to buy a new car.

And wasn't Nationwide stopped from showing that as it was untrue?

The Nationwide ad - they're showing now on UK TV. 

But, there is a counter argument that the update has not rendered the devices unusable.  In my case (and I detest the update), what is offered by the update works.  It's awful compared to the previous app, but a bit like your car analogy, I'd describe it as operating in 'limp home mode'.

Of course you could try legal recourse, but be realistic about what might be achieved.  Good luck. 

https://www.bbc.co.uk/news/business-68711510

What is offered by the update? Because it really doesn't work on my Sonos One. I'm somewhat realistic, if not pessimistic, about what I might achieve...  Definitely never going to get a Sonos again though.

Nothing new - just some badly organised menus and silly graphics for the music services. 

I too wouldn't buy another Sonos but the sound quality is good and I use mine with an alternative control interface. 

The Nationwide ban was for a different ad about bank closures.