I think the X and Y chromosomes are a bit of a red herring. It’s true that the Y is a degraded X, but in birds, males are ZZ and females are ZW. In both cases, the Y and W chromosomes slowly degrade due to their lack of a partner to do sexual recombination with. Eventually, the Y (and W) chromosome is (by default at least) expected to eventually disappear, but this does not mean males would disappear, instead the XY sex-determination system would evolve to replace the Y (and maybe the X too) with something else.
I think the X and Y chromosomes are a bit of a red herring. It’s true that the Y is a degraded X, but in birds, males are ZZ and females are ZW. In both cases, the Y and W chromosomes slowly degrade due to their lack of a partner to do sexual recombination with. Eventually, the Y (and W) chromosome is (by default at least) expected to eventually disappear, but this does not mean males would disappear, instead the XY sex-determination system would evolve to replace the Y (and maybe the X too) with something else.
Right!
IIRC this was also be related/causes to the fact that men suffer more genetic diseases (hemophilia? red-green colorblindness?)