Fred Wilson is excited about Threads, for the right reason, but I don't think it's going to play out the way he thinks. I replied on Threads, hunting and pecking on my tiny iPhone keyboard (I have huge hands btw). I'll expand on it here...

He repeats the folklore that Twitter "killed off" its app ecosystem in 2010. Certainly not at a technical level, the problem with Twitter's developer situation was that they didn't do anything to help products get the attention of users, esp important when we were filling gaps in the user experience that users desperately wanted filled. If a corporate platform wants developers they have to do this. You could even argue that on an open source platform someone has to do it. Users aren't on their own that adventurous., They like to use what everyone else is using, which makes the bootstrap hard. But the platform vendor can provide the magic that gets it going.

However, like Fred, I am excited. Because somewhere in this chaos (a good thing) there is at least the possibility of a developer ecosystem. That hasn't been true for a long time. I don't think that will happen in ActivityPub, for technical reasons. It needs a small amount of centralization to make the hurdle for developers surmountable.