RNC and DNC Conventions -- are they flawed?

With the DNC convention coming up and the RNC convention already in the books, there's something I just don't understand and I think many people can relate to. With all the technology we have in 2016 why do we still have yea and nay votes on the floor and the speaker judges it by which is the loudest?

Surely we can install some buttons or something where votes are tallied in real time from the floor. Who wants to be a millionaire seemed to do it just fine when polling the audience. Wasn't this the case with Roberta Lang in the Nevada caucus when the yea's and nay's came in but were ignored? Isn't that a major issue and doesn't it have the potential to promote fraud? Am I missing something here?

Example --

a reply to: Gumerk

Of they are a fraud at this point. I heard way back in the day, that conventions were held to determine the candidate of either party instead of the circle jerk circus it's become.