[loseyourslinky]

Well the other feature of email in his case is all the GNU email list are archived, you can read his email announcing the GNU project still, I am skeptical any mastodon instance will still be running in 30 years. Mastodon as a whole may still exist, but instances come and go.

[icebraining]

You can archive Mastodon messages too. There are tools made for that, just like with email: https://github.com/kensanata/mastodon-backup