Yep, that’s exactly the sentiment I saw in people’s writing, that email has become almost centralized in practice, even though in theory it’s not. I saw this also generalized, that even successfuly promoted distributed/federated protocols still face the constant risk and challenge of becoming centralized in practice, when a major player manages to capture the majority of the field.

AFAIU, even Mastodon community needs to purposefully work on promoting alternative instances, so that not everybody ends up on mastodon.social…