I was here in those days. Identi.ca was by far the largest instance, but it wasn't nearly the uptime champion. For one thing, many upgrades required days of database processing ... during those times, the site was offline. Indeed, that was part of what led me to start my original single-user instance.
@lnxw48a1 @fu If I may pitch in on on th etopic of "how the fediverse works"...
Yes, you can explain it with the image of email and email providers. But you rely on "freedom" (whose?) to describe a structure that doesn't explain why newbies can and cannot subscribe to other people or otherwise interact with accounts and posts.
A different way is stop putting "freedom" into the centre – which in itself is a rather problematic hierarchical approach as it invokes the imagery of landlords dealing with their rowdy tenants – and explain to people the basics of #federation, from which most of the peculiarities and problems of fediverse interactions arise.
2015 I wrote a piece for Twitter migrants to GNUsocial primarily from the angle of a layperson, explaining the various oddities by pointing to and explaining from federation as the root cause. Perhaps this snippet is of some help: