I suspect because they have moved to a cloud server based system where every command you give the App now has to go to the Sonos server and you have to wait for a response from it back to your system before your system will do anything.  

IMO your problem could be :-
1/ You don’t have superfast internet connection (like me)
2/ SONOS servers cannot cope with the capacity since they forced everyone to update to the new server based App.

3/ The new App is simply a crock of sh#t

I’m running the new app on both iOS and Android, and the latter has more bugs and fewer features than the former. I suspect that most of Sonos’ efforts right now are going into the iOS app … let’s hope that the new Android app “catches up” to the new iOS app.

In the meantime, consider re-installing the v16.1 Android app via APKMirror:

• Uninstall the new app
• Go to apkmirror.com, download the v16.1 app, install it
• Immediately turn off automatic app updates in the Play Store

Unfortunately reverting back to the Ver 16.1 App doesn't help a lot if your hardware has already received  the  forced firmware update which means that even if you do rewind to 16.1 App  you will find that Sonos have bricked important functions from happening in the App such as allowing System settings to being  such as turning off firmware updates, and updating and indexing your local libraries and NAS drives etc.  Shame on you Sonos.

Thanks.  things seem to be getting better slowly!

FWIW, I am running the v16.2 firmware with the v16.1 Android app and it works okay. Not suggesting this for everyone, ymmv, just a datapoint for folks.