AMP doesn't enable HTML email, it was already enabled by Outlook 97.
This is good. We should aim to keep it this way.
There's no apriori reason why a federated messaging system needs to be non-interactive. It's possible to support both immutability and dynamism. You're making assertions that something should be a certain way without actually justifying it.
You could at least provide some formal justification, like you want Email to be an immutable ledger or something. But the idea that Email can't evolve and change and should stay exactly the way it was, pretty much assures its death in the dust bin of history, the same way we lost USENET, LISTSERV, or even XMPP. Old standards didn't evolve quickly, users wanted silly features while neckbeards said don't violate purity of my abstraction.
And today, Facebook, Instagram, WhatsApp, WeChat, iMessage, et al, are the predominant messaging platforms, and email is for spam, receipts, and grand parents.
Also the things you've mentioned there are different things. XMPP was never as widespread as email and is not in any way related to the other two. I am hoping Matrix picks up here.
LISTSERV is simply mailing list software, these do exist today as they did and are used by many open source projects. The most popular one being https://en.wikipedia.org/wiki/GNU_Mailman
USENET, does still exist, particularly for binaries. It's decline was mostly because of the cost to run the services, spam and the fact that smaller web forums were an alternative.
> And today, Facebook, Instagram, WhatsApp, WeChat, iMessage, et al, are the predominant messaging platforms, and email is for spam, receipts, and grand parents.
Not in business it's not, particularly where both parties want to have a conversation and not let those platforms in on the conversation. That is the majority of business and government conversation.
Email is not going anywhere.
