Nome of the service you mention have the async nature of email.
If I want you to be aware of a long article I'll send it to you in an email because if I message it, most people will open it, see it takes more than 2 minutes to read and close it and never go back to it.
If I want you to be aware of a long article I'll send it to you in an email because if I message it, most people will open it, see it takes more than 2 minutes to read and close it and never go back to it.