This is why it's important, as a group, to roll your server. Own the infrastructure of communication and discourse. To utilize open standards for which you or anyone else can create and run their own server, or client.
Protocols should also evolve, or have organized successors over time. If you do provide backward compatibility, please do the best reasonable effort at making backward features work.
I feel like someone stopping maintenance of a private server is way more likely than the most popular chat client at the time shutting down eventually.
In your mind, who in 2017 was still using AIM, blissfully unaware of the shutdown, only to be met with an error page and the loss of their friends forever?
I'm sure most people are like me... over a decade ago, my AIM friends mostly migrated to text messages (and a few to FB Messenger), and any impending doom of those two protocols will be long-preceded by us having already gone somewhere else.
It's still inconvenient. The inconvenience ranges from slightly annoying to "I have lost all my messages and now have to find all of my friends/family/colleagues contact details again somehow".
But the server would be less likely to shut down while there are poeple actively invested in it. With a smaller group, the maintainers can be held more accountable.
> I feel like someone stopping maintenance of a private server is way more likely than the most popular chat client at the time shutting down eventually.
I have been hosting my own Matrix homeserver and my 4+ years of service life seems to be longer than 80% of Google services... :)
(Admittedly I am just joking with this apples-to-oranges comparison, but sometimes it sure does feel like major corporations are trending towards shorter and shorter service lifetimes for their offerings... and this is coming from someone who rode the Google+ train all the way to the last station!)
This is why something like Delta Chat is a good thing. Almost everyone has email, so evolving email to include chat is a good thing. Also, it takes chat away from single entities.
Isn’t an email necessary for a smartphone? I know apple requires one and will create it for you if you don’t have it. On Android, do you need a google account with email?
You don't need to login to Google to use an Android. Only if you want to use Google Play.
Either way, you don't need to personally login with your own account. Often, whoever is setting up the phone (tech aware relative or phone store sales rep) for them will login with their account. For android phones, sometimes the people setting it up will just install customer selected apks from a usb drive; whatever version they happen to have, and when (if) those versions expire, come back to the store to update.
Protocols should also evolve, or have organized successors over time. If you do provide backward compatibility, please do the best reasonable effort at making backward features work.