Look up the history of "political machines", "yellow journalism", "fascism". Democracy has always been corrupted because people are inherently not very good.
Sure, but smart phones & social networks see far more user adoption and time spent than any newspaper during the era of yellow journalism. The scale is just incomparable, and potential consequences far greater.
So what would you replace it with?
They never claimed democracy wasn't the best we have right now.
You mean what to replace the democracy with, or the corruption?