There's already a dead end taking shape with mirror-less bodies designed to look like their film ancestors
Well, I don't think it's a dead end at all. Many of us who happily use RFs don't think it's a dead end at all. Yes, mirrorless cameras have a long way to go, and there will be many incremental advances before it's fully mature, but... that's exactly what you want when creating a new market. Hear me now believe me later, cameras with mirrors (including digitals) will go out of mass production within a decade.