Plus, [email is] built on open, federated protocols, meaning that anyone can set up a server and store their data wherever they like. This is a technical way of saying I can email your Yahoo email address from my Gmail, and vice versa, unlike other closed messaging systems, where I cannot send you a WhatsApp message from my Messenger, for example.
Think about that — I can email anyone in the world with an email address, literally anyone, as long as they have an email address. That freedom is often overlooked.
Email is imperfect, to say the least, but it’s also amazing. We have all of these different services that can talk to each other. You can change your service without changing your email address (as long as you own your domain). It’s all just so cool and distributed.
It’s definitely worth noting that Dvir Ben-Aroya, the author of this piece, runs a company that looks like it’s working on a Slack alternative, so factor that into your enjoyment. My takeaway was that email is still impressively portable.
An open letter to Stewart Butterfield: Why Slack will never replace email | The Startup