Upgrading of, memory or processor, possible?

Not true. If Spotify (or whatever you are using for Music provider) upgrades its platform, it may no longer support your Sonos system that is not running the latest updates. If this happens, and it surely will, you will not be able to play music on your entire Sonos system, unless you remove the legacy devices and install the Sonos updates. At that point, your legacy devices are useless. They are effectively bricked.

Not, not true! Here we are over 1-½ years later and my gen 1 play 5s still work with Apple Music. As long as the Sonos S1 app works it should work. No one is making their platform to only work with Sonos.

I have many S1 devices and Spotify connects and plays with that system as it resides on my WiFi. Sonos could allow users to also access S2 devices. Sonos could even allow users to use both S1 and S2 at once on the same WiFi network either simultaneously or alternatively. Sonos has limited functionality here. Sonos doesn’t have a credible voice assistant yet they disabled Google voice control so now we basically have nothing. I was able to control my devices easily with Google. I literally do not use my S2 devices often bc Sonos has limited functionality in its new devices. There is no technical reason why S2 devices cannot be used on a S1 system. Sonos was visionary by going cross-platform, but now it has turned its back on that philosophy and it is sad to see. I can no longer wholeheartedly recommend Sonos bc it doesn’t work like it used to. Sonos should offer a credible paid music streaming option that is open platform and uploads/downloads Spotify play lists.