In the excellent very hard sci-fi novel Diaspora by Greg Egan humanity has split into 3 main branches that don't really trust each other much.

biological humans, which are subdivided into various genetically altered varieties and the original unmodified humans.

nuclear powered humanoid robots that are not allowed on earth but are perfect for working in space.

fully simulated humans being run on nuclear powered computers buried deep underground for security. Their minds run 700 times faster than normal humans.

This feels pretty plausible to me.