Bultmann makes this statement that:

It is impossible to use electric light and the wireless and to avail ourselves of modern medical and surgical discoveries, and at the same time to believe in the New Testament world of spirits and miracles...

"New Testament & Mythology", Rudolf Bultmann

I think he makes the mistake of pitting miracles against advances in technology by placing the former into the category of old, ancient beliefs and the latter in new, better beliefs. Such a contrast is absolutely unsupportable.

His argument is that of worldviews- that today's modern man will never believe in the supernatural. That may be true, but it does not do away with the existence of the supernatural.