Like @Airgetlam , I think it is very unlikely that Apple could put in any such condition for the use of another company’s product like that, but also like @Airgetlam , I cannot say that for sure.   There must be many factors affecting Sonos’ decision (so far) not to implement Chromecast, and we are all guessing as to what they are

I’ll throw another thought into the mix.  My impression is that Airplay has much greater ‘brand awareness’ than Chromecast.  I can imagine that a lot of Apple devotees would not touch a speaker if they didn’t see ‘Airplay compatible’ on the box - even if Sonos could do everything they wanted without Airplay, and probably do it better.  I suspect that the presence or absence of ‘Chromecast compatible’ on the box would have a negligible impact on sales.  Not zero of course, but the cost/benefit analysis may be very different.

And returning to the title of this thread… Sonos is perfectly entitled to claim to be ‘Android compatible’ on the box, just as it used to say it was ‘iOS compatible’ before it supported Airplay.  But it cannot claim to be ‘Chromecast compatible’ and it doesn’t.

Sonos does allow users to do many things using their Android phones that they may think they need Chromecast for, but don’t.

One other aspect that could be a factor in Sonos supporting airplay 2, but not supporting chromecast could be in the technical requirements of the two protocols.   It’s my understanding that airplay 2 requires a rather large buffer on the speaker side.  That’s part of the reason many existing speakers were not compatible when airplay 2 went live.  That larger buffer was a good fit for Sonos as it meant that a speaker could receive a stream and still be able to ‘share’ it with other Sonos speakers that it’s grouped with.  I can see that as something Sonos thought to be a rather a important feature requirement.

I am completely guessing, but it wouldn’t surprise me if chromecast doesn’t work with as large of a buffer.  And unless things have changed, youtube also requires the receiving device to play video.  The result is that chromecast may not fit as well with Sonos from a technical perspective.

As an android user, I’ve never really felt chromecast was missing. To be fair though, I have Sonos connected to TVs in a few rooms, and have cast youtube to a TV with audio playing over Sonos HT speakers.  Not even sure if that’s technically chromecast or just normal casting.

I suppose listening to music through my phone’s own speaker or through headphones must be clunky as well.  I guess I never noticed in either case.  Works great for me and my needs.

Not sure what you are implying, but I’ll take it as a legitimate question:  When my phone rings and throughout the call, the music just keeps on streaming to the Airplay 2 speaker(s).  The phone call stays on the phone.  

Thank you. So the phone handles this differently from bluetooth music transmission, where the music drops when the phone is in use. Or so it was when I used bluetooth a couple of years ago.

@S1211652 “I had a friend over today with a Samsung S20, and she was able to cast to the Sonos following the directions from her device, so I suspect I do have an Android version issue. She didn’t have other services, so we couldn’t test others.  Still, I am getting somewhere.”

One of the frustrations with Android is that different manufacturers implement it in different ways. I have an Android 5, 6 and 10 devices different manufacturers and all can “cast” Spotify to Sonos from the Spotify App so your problem appears to be more manufacturer or Spotify version rather than Android version.

Deezer which is the service I use regularly cannot cast to Sonos from its App - Deezer have been suggesting it is coming for at least 2 years on their forum

I think Airplay 1 used to  be interrupted by a call.  Airplay 2 is definitely superior in some respects to the original, including having multiroom capability.  I seem to recall that when Sonos announced that it was adding Airplay 2 compatibility, it mentioned these sorts of differences, as it had never supported Airplay 1.