The Sonos system requirements are shown here:
https://support.sonos.com/s/article/126
The Controller App requirements are available here:
https://support.sonos.com/s/article/4875
Any new software/firmware release notes are posted here for S1 App:
https://support.sonos.com/s/article/4941
Any new software/firmware release notes are posted here for S2 App:
https://support.sonos.com/s/article/3521
Unsupported operating systems with limited functionality are shown here:
https://support.sonos.com/s/article/4779
Between those links, you should be able to see which devices/operating system versions are supported currently (fully, or with limited functionality) and during which update a particular version of an OS switched to limited functionality…
As an example, Android 7 has limited functionality as of March 9th 2021 (approx.) with the S2 v13.0 update and the S1 v11.2.6 update.
Just to add that Google themselves no longer support Android 7 too, as shown in this table:
Hope that information assists.