I don't think audiences mistake the technology to achieve an effect with the effect itself.
A lack of awareness of Dariel Fitzkee does not affect an audience's capability in perceiving your examples of: "a vanishing birdcage ... vanishing elephant ... a vanishing statue of liberty ... [and] a vanishing space shuttle" as similar if not the same. The fact that they all vanish is enough.
If you don't believe me, try the following experiment: perform all of them in the same show. Perhaps you could start by vanishing small stuff and work your way up. Do you think the audience reaction would increase according to the size of the object as the performance went on? I would think that their attention would flag and at some point they would "get it" resulting in diminishing "effect". (While this is unlikely to happen, somewhat sadistically I would love to see someone try...)
Take another example. Daryl, in promoting his Encyclopedia of Card Revelations, remarked that if you know many ways of controlling a card but only one way of revealing it that you only know one trick; if you know only one way of controlling a card and one hundred ways of revealing it that you know one hundred tricks (I paraphrase). In practice, you can perform several card tricks in a row, it does not mean you can keep an audience that way without a compelling character, thoughtful organization of material and some thematic throughline to keep audiences engaged.
Variety for varieties sake is helpful, especially for keeping up an audience's interest.
We have a surfeit of methods; we need to spend more time connecting with audiences. Western (and by that I mean as opposed to Eastern) musicians get more effect out of their "limited palette" of twelve tones than we do out of our nineteen effect. Granted, their tones are more flexible in that they can layer them over each other to get differing sound qualities and various instruments producing different sonorities, but it all comes down to communicating an experience.
I do disagree with the broadness of the author's statement and the implied argument that reliance on old technology is what is limiting the advancement of the craft. Methodology is not effect (something that "magicians" often forget) and the focus of the book under discussion is METHOD. Hence the broad statement regarding method (one which is not too far from the truth).
If FISM was that interesting to the public at large, why don't American television stations broadcast highlights?
My fundamental point is that magic practitioners should explore *all* avenues when communicating with an audience. Effect & method are but two components that, when skillfully and passionately coupled with other theatrical components (character, story, costume, scenery, props, staging, movement, music, lighting, and other stagecraft), can create wonder-filled experiences that appeal to a broad section of the public.
Method is a small part of the equation, and a foolish performer (which I personally have been guilty of) will dismiss using a tool because it is "outdated".