Yes, there are people who are good with Alias, but no matter how good you are, Sub-D is always a magnitude or two faster! Always. Most 3D models that get built in the car DESIGN area are in fact form studies. It is incredibly wasteful to let a highly paid Alias guy work on a model for a week that gets cnc milled in clay once and then goes to the trash. In that time you can literally model 5 Sub-D car concepts that are just as good for cnc milling. That’s also why in the concept stage (at least with the German car manufacturers I know about) nowadays they almost completely rely on Sub-D modelling. Also that the surfaces can’t be used down stream is only correct from an engineering mass manufacturing standpoint. For example there are certain manufacturers that use Sub-Ds exclusively for some of their concept cars that get shown at IAA. The amount of designs that actually need to be prepared for mass production and therefore completely redone as “proper” class A surfaces are not that many as one might think.
I think it is definitely true that Sub-D is gaining relevance in industrial design in general and that class A modelers like Alias are more and more shifting down towards the engineering side of the development process. I don’t think it is necessary for an “ordinary” designer to learn Alias nowadays, unless you really want to specialize in the CAD side of design. For everybody else there are more exciting and effective things to come.