I’m part of a small team building www.strings.com and what you describe is basically our reason for being. Rather than squeeze everything into a single profile, users create different “strings” for groups and topics that matter to them. Greater segmentation doesn’t come without its own challenges (esp. related to insulation and echo-chambers) but smaller, more relevant groups/communities/strings do feel more authentic. I’m hopeful that we see more of this in the future.