Sonos does fully support Android.  Airplay and Trueplay are impossible on Android because of device limitations, and Sonos apps onAndroid devices do everything else that can be done with iOS.  The Android app can also play tracks stored on the phone.

For the most part, airplay functionality isn’t needed, and not the best way to stream audio on Sonos, since you can stream most services directly.  For other sources, you could use an aux line in (Five, Port, Amp), TV source (Arc, Beam, Amp) or bluetooth (Roam) to bring the audio in to your system.  That said, the second Apple works a deal with Google to allow airplay on android devices, it will be supported by Sonos.

As for trueplay, it would be nice to have an alternative besides Apple devices, but it’s a one time setup that can be done with a borrowed iphone.

You can surely build and think of equivalent features for Android, they might, however, require some additional work or additional investments? That would be okay though. But I don’t feel like they fully support Android or take it seriously. I’ve gone through the landing page of some products, and the list of key features, only to realize that these things are tallied for iOS and don’t work with Android. Maybe it’s also partly just their marketing that is at fault, but it makes me feel there is no feature parity.

I'll give you the benefit of the doubt and assume you are just poorly informed. What sources of audio do you want to play?

You’ve mentioned your feeling a couple times now, and have made some rather broad assumptions about what it would take to duplicate trueplay/airplay on an android device.  The reality is that the Sonos app is a controller, and it makes little difference whether you use android or iOS.

Well, that’s not exactly the point, since I just want to be flexible and have as little friction as possible with my sound system, regardless of what I might want to play. Also, to be fair, at some point in the past I already asked Sonos support about this topic and they simply answered plain and short “android doesn't have that features” without providing alternatives or further details, even after I asked for some.

But the two everyday use cases are probably Spotify (I know that works with Spotify Connect) - and playing local files (e.g., mkv) from my NAS or Windows machine.

Airplay for Android is an Apple/Google issue as has been previously stated. Why no Trueplay for Android was answered in 2017 in the link below. So…what exactly can’t you do with Sonos on Android that is due to Sonos just refusing to integrate on Android devices?
 

@scientia 

Did you really “Best Answer” your own question???

It’s not specifically about AirPlay. I’m just saying Sonos should provide a similar feature for Android. Same with Trueplay - for whatever reason they currently don’t have it, they should provide an actual solution rather than “buy or borrow an iPhone”? Even if that means that Android users have to buy an external mic.

Sonos doesn’t write OS level software, like AirPlay 2 is. They can’t rewrite the Android software to do a similar thing, that’s up to Google to do so. I get your desire, but you should be asking Google to rewrite the OS, not Sonos. 

It’s not ‘for whatever reason’, there are very specific reasons why android doesn’t support airplay and trueplay.  Even if Sonos could build their own version of airplay through Sonos, why would they?  They designed their speakers to stream audio from services and local libraries directly, which is a much better solution than airplay.

As far as buying an external mic, it’s a idea that’s been mention before, lately with the idea of using the mic on the Sonos Roam for this purpose.  I’m not sure why it hasn’t been done yet.  Could be that cost and potential price don’t workout for the projected market, or Sonos has some other plan.