Thank you for your detailed response.

Certainly, we all self-segregate to a degree. For a starter, our time and energy is not infinite. We have to be selective. It is a slippery slope, though. If you do not block people for having different opinions, you are in the minority. People justify blocking others with appeals to their limited time and energy, but the reality is that is just an excuse for their narrow-mindedness. Maybe, because I have been engaged in the online world since the mid 1980s (Compuserve was my gateway drug) I have developed a skill of just ignoring nasty people. As a semi-public figure, I get a lot of abuse, but I have never ever blocked anyone.

I see two issues in this. One is personal behavior of self-selection of what we see and hear, which is unavoidable and necessary. The other is the architecture of the medium in which personal interactions take place, which are more or less restrictive on those interactions. On the one extreme, you have a city park, where the space is open and anyone can come in and out and you cannot easily shut anyone out. In the middle, are mediums like an academic conference in which you have breakout rooms where you can listen to one particular conversation but can move to others when you want. Then on the other extreme is a closed members-only club that only those invited can enter.

People think Twitter and the other major social media platforms are parks but the restrictive algorithms turn them into conferences. People like to think that Mastodon on the like are like conferences but they are really closed clubs that you can only enter when allowed by a gatekeeper. Sure, once you are in the club, you have some mobility, but you are mostly stuck in whatever club let you in. I know some people who want to join Mastodon but can’t find an opening, see them asking around for an invitation from a gatekeeper. I’ve never tried to join Mastodon because I am not interested in anything that elitist and restrictive.