It was. It's called Usenet.

And Usenet even included posting a single message to multiple groups, and people from both can respond.

I would be thrilled if the followup to Reddit is Usenet but with working moderation.

We’re there ever attempts to skin Usenet with friendly interfaces like old reddit?

Any resources you can point me to? I’m really interested in these concepts.

There is activityPub which is used by mastodon (a twitter clone). Some peoples are making reddit clone that federate with activityPub a bit in the same way that emails federate.