Separation is not the issue here, the separated lanes have to cross just as well. They are only less likely to have cars run over cyclists, because now the guy

Separation is not the issue here, the separated lanes have to cross just as well. They are only less likely to have cars run over cyclists, because now the guy with the perfectly unobstructed view is forced to always yield to the guy who is driving around huge, dangerous blind spots. On-demand lights are even worse, now the guy who isn't a danger to others is legally obliged to preventive defer to those who are even if nobody is there, that's like saluting the portrait of the dictator.