This!

Instead, you create a link with a comment in Signal to a group of friends, copy that to a few other Signal groups who are mutually exclusive of those other groups, then paste into a few Discord groups...

Literally a manual social network.

If you're wise enough to use Signal, why would you also be using Discord?

It's the original FB problem all over again: if that's where all the people are, you don't really have much choice if you want to reach them.

Newsblur has this feature although I don't think it's used much.

This is where that gab project from a couple years ago was amazing (although the most generous thing I can say about the user content created by it was that it was not amazing lol). it had an extension you would install and it would overlay a comments section on any webpage on the internet.I would love to see something like that but with properly threaded comments and an easy way to subscribe to specific communities commenting, or ideally, federated but you could choose the communities you wanted to overlay moderation from. even better if it has support for easy account switching so you could bin your comment into the proper group for the level of moderation it would pass.

activity pub almost does this but comment threading has been universally garbage on every instance I have tried (how hard is it to thread stuff like comments on hacker news are threaded????) but the method is wrong in that you scroll activity pub feeds instead of surfing the net and finding the rich and interesting comment sections for what you are seeing.

Much like Reddit, or you know, Hacker News.