>Despite that, they're still heavily used

This person is in a serious bubble. Mailing lists are not used by billions of people.

>Mailing lists require no special software

Even ignoring that most social media are accessible via a web browser instead of their dedicated app, this is just adding more complexity than having a single app for people to use. Everyday people want a single way to do things.

>Mailing lists are simple

No, you have to figure out how to configure a mail client and how to properly respond to things and is no where as user friendly as typical social media apps.

>They impose minimal security risk

Using an external service lets you outsource security to dedicated security teams as opposed to no security team or a volunteer security guy.

>They impose minimal privacy risk.

I trust the privacy of social media than some mailing list where the admin could secretly grep the contents of it with no over site.

>Mailing lists are bandwidth-friendly

The average internet user is scrolling through tiktok, streaming videos. Bandwidth is not a big deal anymore.

>Mailing lists interoperate.

Social media have features for reposting between different groups. There is also copy and paste and links.

>They're asynchronous

There are social media like facebook which are also asynchronous.

>They work reasonably well even in the presence of multiple outages and severe congestion

Social media is also resistant to outages and have dedicated teams towards keeping it online.

>They're push, not pull, so new content just shows up.

Have you not been on social media for decades? Pushing content to the user is the norm.

>They scale beautifully.

Social media scales to billions of people using them.

>they're relatively free of abuse vectors.

You can't pretend that spam does not exist.

Mailing lists are not mainstream and they never will be. That way of operating did not resonate with people at the scale that is needed to reach even tens of millions of people. Social media works. Chat apps work. Forums can work.

> I trust the privacy of social media than some mailing list where the admin could secretly grep the contents of it with no over site.

This will only allow them to find the text of the messages, which is public anyway, so what exactly are you worried about?