The goal of decentralization shouldn't be a uniform distribution of instance sizes. That's unnecessary and unrealistic.

Decentralization prevents any one entity from exerting too much power over the whole ecosystem, allows cultural differences between communities, and enables semi-independent technical experimentation by instances so that successful innovations can percolate. These are the things that made the web successful. Mastodon has all of these, and isn't in danger of losing them.

One question is about how the current level of (de)centralization will change. I think two divergent paths are possible.

1. Instances continue to be volunteer run (and, in my ideal world, organizations like universities and media outlets will run instances for their members/employees). In this case, decentralization will continue and even increase.

2. There's an influx of commercially run instances. If this happens, there are inevitable centralizing trends — see how Gmail dominates email.

@randomwalker I think you might have under-analyzed the likely #evolution of the volunteers in world 1. They're going to be confronted with increasing hosting and especially moderation costs, which I think will drive them to professionalize and to make it harder for non-professional instances to federate.

That is, existing commercial entities don't have to adopt #ActivityPub for it to centralize; the volunteers could adapt in centralizing ways too.