Back when they started on that, we were worried they were going to kill ActivityPub like how Netscape got killed by IE durring the browser wars. EEE (Embrace, Expande, Eliminate), adopt the protocol, expand its capabilities while including propriatary portions of code, and lock the competition out when market saturation is achieved.

The issue is that fedivers residents are a bunch of tech-literate weirdos and called this bullshit the second the news dropped, and are 100% the type of people who make forks as soon as something like that would actually happen. Piefed being the perfect example, this part of the internet is perfectly fine just picking up their things and making something else (and we love it here for that).

Also, Threads has introduced extremely strict rules for servers that want to federate.

Entire Fediverse server applications are incapable of following all these rules, either technologically or by concept.

For example, IIRC, Threads demanded a full public timeline. Hubzilla, (streams) and Forte do have that feature in code. But it's intentionally turned off server-wide by default, and there's a very good reason for this and for just about no serious admins of public servers ever turning it on.

You can but iirc it takes quite a bit of bidirectional effort to enable that. Thankfully!

you’re lucky if you can even finger a user between systems

I'm sure the gals at the blahaj zone are up for it

Lemmy and history, no. On Lemmy you can see comments from Mastodon and posts (toot with a Lemmy community pinged inside. Which is rarely done but happens). But not the toots themselves
Piefed now allows to directly follow accounts (similar to Mastodon, Friendica, etc) and you can start getting the new toots after following an account https://piefed.zip/c/microblogs

From mastodon viewing lemmy stuff is nice enough. It would be great if you could seamlessly crosspost and share between platforms.

It's not like I can view a Mastodon user's history on Lemny, right?

afaik you can

Lemmy is all about groups. It doesn't have any way to connect to and interact with single users.

Mastodon, on the contrary, is all about single users following single users. It has no support for groups whatsoever. Mastodon users can follow Lemmy communities, yes. They can reply to posts, but in a very Mastodon way (automatic mentions, they'll probably insert hashtags etc.). Seeing (almost) the entire conversation is the default on Lemmy and extremely tedious and anything but straight-forward on Mastodon. And starting a new thread in a Lemmy community from Mastodon is difficult, nobody knows how to do it right, and whoever tries it will clash with Lemmy's culture.

Stuff like Friendica or Hubzilla is somewhat more general-purpose. It can do both. But I've yet to see a Lemmy user subscribe to a Friendica group or a Hubzilla forum (the opposite does work).

Of course. I find "social media" a suboptimal term anyway. A good term for the concept is the "participatory Internet".

But if we are going to use it, then it's just media that is produced by society at large as opposed to paid journalists or authors. Meaning Usenet is social media.