I think this has somewhat happend already, but DE blades are probably not going anywhere soon.
20 years ago I would have probably had the choice of 10-15 different brands in my local supermarket.
Today one brand, if I'm lucky, to different ones from the same brand.
However, look at it this way, if you see the amount of 20-30 year old NOS blades on e-bay, whole cartons of the stuff.
And don't forget that most here already buy there blades in "developing" countries, where DE shaving is still the norm.
I doubt that even if production ceased, we'd be lacking blades in the next 50/60 years.
Choice yes, blades, no.
FB.