Speaking of the Abacus, I remember watching the local Vancouver news many years ago where they had a race between an abacus and a new fangled adding machine. The Chinese man running the abacus won to the embarrassment of the secretary on the adding machine.
I think the reason the adding machine wins out in the end is the ease of use. I don't know anything about HTML but as long as Flash is the easiest to use and has the most options, it will be popular. Flash isn't standing still either, their beta version 10.1 is what is making these new devices able to run youtube.
http://www.anandtech.com/show/2876