Just a quick note on the email point — the specific thing I was responding to was this from TFA:
"Many people, especially younger devs, have never seen a real mail client like mutt. In their minds they may picture an overflowing GMail inbox full of top posted replies all mixed together from different projects. That’s not an enticing image. Perhaps this article can start these developers on the path to rediscovering the care and engineering that went into classic email clients."
My point is that this is nostalgia for terminal-based email clients.
Need not be. The important thing with mutt is that it's standards compliant, it helps follow the conventions of these communities, and as a plus it's easily configurable and scriptable. If there are GUI tools that bear the same properties, they are equally viable (AFAIK Claws comes close).
This doesn't really help your argument, because that's not how people use, say, gmail in 2018.
> the problems of the past are precisely what got us to the present
If you're comparing mailing lists and Github, I don't think that's true at all. Github started with Git, then they said "let's tack this other stuff on top of Git to improve the workflow". It's not like Github was what happened when mailing lists evolved. Maybe you can combine the best of both technologies.