Almost nobody in my circles uses email for personal conversations anymore. People don’t share their email when you meet at a conference. You don’t join the X tech discussion group over email (anymore).
This also implies only talking to people you already know, no opportunities to join or start communities.
And that’s still besides the point: just imagine that your email account is cancelled tomorrow because they don’t like something you said in a mailing list.
I don’t doubt what you’re saying about your circles. I live in a different universe. If someone only communicates through Twitter, etc., that’s a useful filter for me. I don’t have a Facebook account.
“only talking to people you already know”
Far from it. For example, the contact information for an author on a scientific paper often includes an email address.
This also implies only talking to people you already know, no opportunities to join or start communities.
And that’s still besides the point: just imagine that your email account is cancelled tomorrow because they don’t like something you said in a mailing list.