I could sort servers on the joinmastodon.org list by proximity to 150 active users (Dunbar's number), I don't know if that would be an improvement. The working set is still 60 top active ones in each category.
For example, sorting the "I am ..." set like that puts writing.exchange, lbgt.io, and monsterpit.net on top, and mastodon.social on the very bottom
On the other hand I do not see a compelling argument for why exactly Dunbar's number (number of personal connections you can maintain in your life) should be used. I don't think most people go into social media expecting to know every single person on their server, and having a headroom of people you don't know might even be a positive thing.
@Gargron I think the problem is, that the possibilities to find an appropriate mastodon instance are pretty limited. The search interface on e.g. joinmastodon.org looks pretty, but a new user never gets an overview of all mastodon instances. The consequence is that some small instances do not get recognized at all. I think a simple table like https://podupti.me/ or https://the-federation.info/ can be much more handy. Uptime should always be specified, because it is a very important criteria.
This Mastodon instance is for all people, who are looking for alternatives to all the common commercial communication platforms, which you pay with the loss of your privacy. This instance is is not focused on any particular niche interest. Be nice to each other 😊