Services such as mastadon and nostr are doing way, way too much. Why in the hell would you want to get into the content management and distribution game when we already have really great systems for doing that? If you want something with a chance of working, you need to do it using entirely COTS components. You are in luck, because we have all of these and the problems are well understood.

The core problem is actually content indexing, so that users can filter by author, date and tag. Software that does this (such as ElasticSearch) is very common and well understood. So what is the missing link? Content sources need to make it easier on the indexers, so that you don't have to be an industrial gorilla like Google to get it done.

How do we make this easier? Via DNS and RSS. All that's missing are TXT records to:

1. Provide a URI with the available tags/topics/authors at the domain (authors are actually tags after all)
2. Provide a template string which we could interpolate the above two (and date / pagination info) into in order to grab the relevant RSS feed
3. Provide a template string describing how users can reply to given posts

Nearly any CMS can do this with no code changes whatsoever. Anyways, this allows indexers to radically reduce the work they have to do to put content into the right buckets. It similarly provides a well understood means by which clients can interact with posts from nearly any CMS.

From there retweets are actually just embeds tagged with the RT'd username and RT author. Similarly, replies are just new posts but with an author from another server, hosted locally. Facilitating this would likely require some code change on the CMS end of things, but it would be quite minimal.

The fun part is that this is so flexible, you could even make it a "meta" social network (it really is unfortunate Facebook camped this name) which pulls in posts from all the big boys. That is supposing they actually published DNS records of this kind. No such cooperation would ever be forthcoming, so such a social network would necessarily be limited to people with hosting accounts.

This is of course the core reason we do not and will not have decentralized social networking despite all the tools we need being right here, right now. This is not to say that such a system is not worth implementing, or that it would not eventually replace our existing systems.

The simple reality is that the users themselves are the core problem. The hordes of freeloaders who want free attention will always far outnumber those willing to pay for a hosting account to interact with people online. As such, having to monetize these people will necessarily result in the outcome we have today, repeated ad infinitum.

Any user of such a decentralized system would have to adjust their expectations. Are people willing to sacrifice nothing to interact with you really worthy of your time? Maybe being a bit more exclusive isn't such a bad thing. This is why the phenomenon of "group chats" has become ubiquitous, after all.

Nevertheless, I find all the group chat solutions such as Matrix to be overcomplicated. Would that they have taken such an approach to solve their coordination problems as well.